I think you can make an argument for both, but it's probably ceiling being lowered first.
Floor MIGHT be lowered because of what you said -- the average APAC teams underperforming, especially with current meta. The thing is we can't really check... they may have improved relative to other regions but the same teams qualify to intl's every time so we can't know for sure.
Ceiling is definitely lowered because the most consistently good teams (namely DRX and PRX) have gone from being considered a favorite every tournament to being more dark-horse picks. And while GenG has improved drastically they aren't as dominant as they probably should be (and also they have really bad showings sometimes... GenG was a Champs favorite that got grouped, that's never a good look)