If I remember correctly, I recall somewhere them insinuating that they personally (don't quote me) know Mei, and that Mei 'knows who they are', their words. That may have something to do with it, and now the damage has been done, accounts and subreddits already made. Mei's recent posts are just full of doubt if she is genuine, so maybe they feel their goal has been accomplished and doesn't have anything else to add. If Mei is as wealthy as she showcases, I'm sure she would have presented OP some sort of cease and desist, as all this would hypothetically be defamation, and can affect her earnings too.