The exact quote before the Oda interview begins:

"With 105 individually collected volumes of ONE PIECE stories, Oda-Sensei is the rare manga creator who has remained a singular lead-increative voice charting an ongoing, serialized mythology. He plans to personally close it out by 2025."

https://www.netflix.com/tudum/articles/what-is-one-piece

A summary of claims when the manga concludes:
https://en.wikipedia.org/wiki/One_Piece#Conclusion
The first mention of 2025, then maybe 2024, was in the fall of 2019.

The manga´s release schedule:
https://claystage.com/one-piece-chapter-release-schedule-for-2023

Oda is proven to be good at given estimated timeframes. Give or take a year:
https://thelibraryofohara.com/2020/11/24/when-did-oda-say-one-piece-will-end-with-official-sources/
Watch the video. Notice how in 5 years and 2024 became 5.5 years (from 2019) to 2024 - 2025 and now firmly 2025. Likely due to the manga´s slowing release schedule. Covid, OPLA and the recent eye operation are reasons but also due to none of this being planned out to a week exact.

Vol 61 is confirmed to be the exact start of the second half of the series. As in only 50% are left. Give or take a volume. What can´t be predicted are "Oda Breaks". Those could push the end into another year. See link 3. Lastly, this is a press release and Oda is a primary source for all estimates in the first link. The highest source possible. None of the statements were ever walked back. OP will likely be a 120 or so volume series and Marineford is only 31 chapters long. Brace for a short stay at Elbaf and the "Final Saga" began on August 29, 2022 with chapter 1058 during volume 105.

How the arcs break down:
https://onepiece.fandom.com/wiki/Story_Arcs
Wano is 16 volumes and 149 chapters. The final arc looks to be in that ballpark.

Lastly, the anime began to feature canonical deleted scenes since Dressrosa (Sabo flashbacks), outside of that one time in Loguetown in 2000. At least the Ace LNs are (broadly) canon, all (non-canon) feature films since 2009´s Strong World have canonical info in them. Recent SBS segments (tankobon FAQs) had canonical info about events and revelations not shown in the manga. Zoro´s lineage and a Yamato flashback are the latest examples. Not all answers will be "on the page" in the manga, so be prepared.

I also read EU/US comics and am a librarian.
Manga-Masters, My ANN-Lists + Imdb

Regardless of what anyone says about how long One Piece has gone on, I love seeing creators so passionate about their work and the world they've built. 2025 will be the end of an era...

http://i.imgur.com/LxhWm.jpg (will reformat this some day…)

Isn't being a singular lead creative the overwhelming majority of the manga space, outside of novel adaptations?

And glad he still feels like he has a concrete plan for an ending.

I think the quote may refer to how Oda-Sensei seemingly hasn't given any other creatives a story-changing say in how his story plays out. And in that sense, it is rare. Take Bleach: the editor(s) had a major effect on the story several times. Such as hurrying the end of the Karakura arc (they invaded Soul Society sooner than Kubo wanted) and extending Ichigo's assault on Hueco Mundo (Kubo didn't want to spend that much time in Hueco Mundo).

And I remember many mangaka talking about having to negotiate with editors on things.

Take what I said with a grain of salt, my memory isn't good.

One Piece won't be gone, but it will be missed. I wonder if Oda-Sensei is going to make another story or retire? And if so, will it take place in the One Piece universe or will it be something original?

I'm a jack of all trades but master of none. Too many jars and not enough hands.

Editors have a documented effect on One Piece and Jump´s editorial is one of the tightest in the business. I know that Bakuman is fictitious but it goes over how editors affect authors big and small. Read or watch it. Editors arguably made Dragon Ball the success it is (from day one, as the already successful Toriyama was made to redesign Goku). The most famous editor in Jump history?: https://dragonball.fandom.com/wiki/Y%C5%AB_Kond%C5%8D

Editors made Oda redesign characters, Axe-Hand Morgan is the first such example. They made Shanks lose his arm and are the reason the Worst Generation exists. And with it Law. Oda was told that Sabaody needed more suspense and he made basically all of them up within hours. One of the most creative single sessions in the history of manga! Editor also get to decide what is important enough to put in a chapter or not. Senor Pink´s backstory (100% Oda´s writing) wasn´t supposed to be in the manga but his editor liked it so much that he made Oda find the page space. Editors are also where the new Oda breaks come from but Oda is the kind of guy to draw out of a hospital bed (with the help of the Naruto mangaka). Oda´s editor also worked on the live-action show with him and Shueisha is one of 3 production companies on that show (+ Netflix).

One-man armies exist in US comics, the audience for the article are Americans, but it´s usually a 2 person team (+ editors, inkers, colorists, etc). This could be why the "rugged individualism" is highlighted. Even Shakespeare, who is brought up, has known co-writers, so this is all a bit questionable. The editorial turnover rate for OP is high-ish but not unusual for Jump. They are rarely static. Again, see Bakuman. 2023´s No. 12 could very well be the final one: https://comicbook.com/anime/news/one-piece-manga-new-editor/

Anyway, if the manga ends in 2026 then it does but we continue to go down a one-way bus ride with all destinations broadly mapped out at this point. The late 2020s are out of the window and Oda and Jump want people to know. The ending is also known within Jump´s upper echelons to ensure that it will finish no matter what. Oda could be the most overworked man on earth rn but his happy hell will soon find an ending and he stated that OP will be his only long-term project. Oda turns 49 next January.

Edit: The next anime film should be the last to release while the manga is still ongoing. Expect Toei to lean into that to create crazy (non-canon) stakes. Also, the crew is full. Now more than ever. Time ran out.

I also read EU/US comics and am a librarian.
Manga-Masters, My ANN-Lists + Imdb

Sorry for the late reply. I meant to to do so last year. But with with new information coming out it is now more important to set some things straight.

Your first mistake was trusting Oda. Your second mistake was trusting Shueisha. Your third mistake was trying to convince others to trust both of them when it comes to One Piece.

There is little planning and the man himself doesn't want to tell us how much he makes up on the spot. Instead he talked about playing Pokémon Go or promoted the CG muscial shit fest that was Film Red. The rates of completion he has given over the years and his time frames for ending One Piece don't line up with reality. I am vindicated by the announcement of "Goda"'s three week break of scheduled maintenance for his body in which he confesses not knowing what the titular treasure, that awaits towards the end of the series actually is. This also shows a lack of leadership from the editors side.

Allowing retcons, lack of character growth (especially Usopp's regression), out of character acting, nonsensical unexplained off-panel power-ups of secondary characters to have them participate in battles, the dilution of drama and action by including too many unimportant jobbers, the recent scribbles and his problem with drawing proportions (Enma is a mistake a student wouldn't get away with) and most of all the recent power scale explosion with characters discovering a hidden power/inherited potential/anything not earned through effort within themselves/or in others only to (in one case succesfully copy and) master it moments later. No build-up, maybe a flashback with information that wasn't present in previous flashbacks.

The few times we have been told of, where the editors made Oda rack his brain to a postitve effect do not make up leading to Shanks becoming a cripple. One of the worst situations in history, that editorial meddling combined with a clueless start-up artist has led to. Why does he even need an editor anymore? In a recent message he said he will continue to do whatever he wants. It doesn't matter since to other very very succesful manga ended, for the most part with a horrible war arc. Expect Oda to do the same with or without an editor. The young Oda had style and a sense for impactful writing, is said to have been more abrasive and argumentative towards his editors. The current Oda in many cases writes like a confused old man trapped inside a severly worked down middle aged body, clincing to a style of work he developed in his younger years, reigniting that old spark rarely. One Piece will never be finished in 2025, 2026 or even 2027. The amount of characters that still have important roles to play the mysteries that still need uncovering the puzzle pieces still needed to find the final treasure and most of all the numerous long-winded battles, sieges even wars that need to be fought will take years considering the length of the new world arcs. Except he just forgets 2/3 of all those things he set in motion and sometimes even outright foretold in the narration bubbles and rushes forward like a wild beast without any sense.

tl;dr Trusting Oda, in most cases leads to an epic fail.