Citation needed.
Most Japanese illustrators do not care about the US/EU, and many of them even hate gaijins. If you haven't noticed, anti-Americanism is very strong on the Japanese internet.
But sure, if you want examples of this trend try searching Pixiv by title for stuff like "twitterまとめ" [1], " or "Xまとめ" [2], meaning a usually monthly compilation of illustrations that were posted to Twitter first. And that doesn't even get into the artists that stopped using Pixiv completely because they got bored of it or their account was banned.
[1] https://www.pixiv.net/en/tags/twitterまとめ/artworks?mode=safe&... (apparently these links don't capture the fact that it's a title search and not a tag search, you have to be logged in and set it manually)
[2] https://www.pixiv.net/en/tags/Xまとめ/artworks?mode=safe&s_mode...
By "anti-Americanism", I'm insisting that a good number of Japanese anime artists see the ban as a beneficial feature, not a disadvantage. They would see this as an automated "Sorry, Japanese Only" filter.
They're very likely perfectly fine with Americans and foreigners in general seeing and sharing work without trying to change the culture of the site (which is fair and something more communities need to start expecting, there's an increasingly popular idea that various hobbies have been ruined by uninvested "tourists" that come into the community, force it to change to accomodate them, then leave after the original audience has been alienated).
The social divide is getting really worrying these days.
Compared to what? Line, or do you have something else in mind?
Besides, LINE is extremely unpopular among otaku in Japan (yes, racism).