Gunka no Baltzar changed publishers last year and moved from the Seinen Comic @ Bunch by Shinchosha to Bessatsu Shounen Magazine by Kodansha. The magazine AoT ran in. Dropping it "down" to Shounen seems to be only logical at this point as it´s an ongoing manga. The split begins with Vol 15 and furigana is now used. It wasn't before: https://pocket.shonenmagazine.com/episode/3270375685381843094

Who knows how reprints will handle Vol 1-14. Does anyone else have a better idea or more knowledge?

Edit: No pushback after a week. Shounen it is.

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