I think it comes down to where they went after the rooms closed. Some went to other platforms like imvu or second life, some rped here or .com or Ayon when it appeared, and various other such sites. Some simply stuck to Yahell messenger till Yahoo killed it. I think a lot just went into personal stasis.
I've been wandering the Internet since Yahoo! Chat tanked. I disappeared into IRC after MuuTuwon pulled the plug on AyeneeIRC, started a community that lasted for a few years before moving on. Forums, tumblr, Discord...and now back here again on an utter lark. Let me tell you, there are some downright culty communities out there.