Flat chest humans and anthros are allowed. But they just can’t be or look too much like human minors. Foalcon and non-human, anthros(provided they don’t look “too human”) are still in the clear.
Nw, this is a fictional case we’re talking about. It’s really hard to define a line between a flat chest or a minor. Most of the time, if they are characters who we know aren’t underaged and don’t look underaged, we feel safe about it. But in the case of CMC, who we know are underaged, it might be a little tricky territory.
I know it doesn’t make sense, neither does this stupid law which is in effect where the servers are based. But they can’t do anything about it. Sorry.
Personally, I think censoring fictional materials is bullshit.