I mean, context.
When, say, Nyaru appears on cam you see a genki girl a little older than she pretends to be that people joke is "fat".
When Riro appeared on cam, people here speculated about anorexia and her bandages hiding cutting marks. While she was maybe, maybe not joking about IRL meetups with her "harem" of super special supporters.
I think it's fair to be a little more concerned about the latter than the former.
And talent welfare aside, as a vtuber corp, you really don't want to be associated with anything even remotely looking like it might lead to genuine prostitution.
Aviel has plenty of reasons to intervene.