I don't think a general solution would be required in this instance.
In this case, as I understand it, the abusive actors did the following:
1) tried to join with an abusive name
2) impersonated a student login and yelled abusive things in chat
It seems that (1) could be solved by blocking connections from any user name that is not on a whitelist of approved student names and nicknames, and (2) is most likely an issue of someone else accessing the student's login credentials, so it could potentially be mitigated by multifactor authentication.