It was only anonymous for the women speaking there, but not for the men they were speaking about, hence the justified outrage, since anonymous strangers are gossiping/slandering you in a public online space behind a 2$ entry fee.
Would you also support if men had their own such public "safe spaces" to gossip anonymously about real women with their names? I can assure you it would be shut down immediately.
So then why do we allow double standards where only one sex should loose their right to online privacy?
Because like the earlier comment points out, letting anonymous people trash talk real people and name them is a core feature of 4chan.
What happened on the tea app were probably not knowable, observable or refutable for those actually being doxxed or slandered.
That isn’t me saying 4chan is absolutely morally in the clear, but it’s still quite a significant distinction.
It seems like your argument is based on (1) the discussion being slander (assumption); and (2) the idea that you could refute it if it were public (good luck, low credibility, also most men would immediately respond with vulgar name calling and - at least if anonymous - threats).
The problem isn't that the site is anonymous. The problem is I, as a man, have no way to check to see if it contains false or defamatory information about me because you can't sign up as a man.
I have no problem with anonymity. But this site exists to allow spiteful women to break the law.