What happens if you forget to renew your domain name, or someone steals it by the trademark rules? Would that person then gain access to your encrypted chat?
If it's just a pointer to a merkle root for the admin chain then they don't get access to the encrypted chat, they'd still have to request access from an existing user.
You could simulate that today by say creating a weird named team (say random GUID), adding a text file like .well-known/keybase-team.txt on the domain with that team name, and then encouraging people to sign up via something like:
keybase request-access `http GET http://example.com/.well-known/keybase-team.txt`
You could simulate that today by say creating a weird named team (say random GUID), adding a text file like .well-known/keybase-team.txt on the domain with that team name, and then encouraging people to sign up via something like: