If so, why so? And if not, why do you think this is the case (when compared to shoujo which has more of a reputation for a particular art style)? How did this difference between the demographics develop?
For an example of what I mean, see this tag; the fact the term "shoujo-esque art" can be used here, when (in theory) shoujo only applies to the demographic.

Sorry if I've done something wrong; I'm not new, just easily confused.

It seems like artists can be more experimental with the art style when it comes to shounen series than they can with shoujo series. However, that being said, there's no deny that there are some shoujo creators out there who do deviate from the "norm", but most of those seem to be either from the 80's and prior or are from artists who do more than just shoujo works.

In fact, for some reason, even josei series seem to have a wider variety in art style than shoujo series.

[img]http://www.dragonflycave.com/wpay/mew.gif[/img]

The is a wider Jump art style in terms of how page layout, posing and so on works so I have to go with yes on that alone. The endless Dragon Ball clones should also be mentioned and they existed for 3 decades. The style of FotNS is also widely imitated but both male demographics use it.

Shoujo is highly associated with the romance genre so the accusation of limited art styles isn´t totally off point. The same thing happened with vintage romance comics in the US as they gave us Pop Art.
[img]https://englishrun.files.wordpress.com/2016/03/perfection.jpg[/img]

There are also types of superhero art that can be divided by generation. Jack Kirby to Neal Adams to Jim Lee are the big ones. You can also say the same for (teen) manga which are more trend-focused than adult manga. Good on AoT for breaking the mold as this allowed other less... clean art to be widely accepted. See One-Punch Man.

Edit: The 8 and 1/2 parts of JoJo (Rohan counts) went through ALL the art styles:
https://comicvine1.cbsistatic.com/uploads/original/14/149324/3515270-1314632387-031.j.jpg
Jolyne got more buff, huh. Not as many styles as HxH but still up there when it comes to artistic "inconsistency". Things get real crazy once you throw in the anime art styles, the games and the many paintings. The 6 Shounen parts are still as artistically shounen as it gets with the exception of the Rohan spin-off. Part 8 and a lot of 7 couldn´t be less Shounen if they tried though.
The switch in the demographic market an easy to spot difference outside of going monthly. Too bad that Part 6 had to be run in Jump. Big mistake.

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