Can all users be invited to chat? (Assuming they have sufficient reputation to talk in chat, that is at least 20 reputation points.) Does every user have a chat profile?
I have tried to search a bit here on meta and the information seems to be contradictory (emphasis mine);
- In CW answer to How do I contact other users? I read that: "Some users are active in chat, and you might be able to set up a "private" chat room for you and the user you'd like to contact by visiting their user profile on chat."
- In Shadow Wizard's answer to What makes someone a chat user? I read that: "If you want to invite someone to chat, the only single requirement is for that other user to have 20 reputation points."
I have even tried to test this myself. I searched for users which have at least 20 reputation points, but the accounts are relatively new. (So that the probability that they some their comments have been moved to chat is lower.) For example, this user on math.SE. But when I tried to search for this user in chat, I did not find their user profile.