From what I can tell, artists do not get into (severe) trouble for choosing the wrong age ratings - unless you did that for 'a lot' of images.
You've been on NG for quite some years. I'd advise you to read the rules again. Maybe something has changed since you first registered.
Yatsufusa
What did you get banned for?
BetterDonut
I mislabeled my suggestive artwork as M rated instead of A
it could also because I was marking my lower effort doodles as being for the art portal