Description:
There are lots of problems with the current process of disabling an account that could be solved, if there would be a way to rename the account federation wide before disabling it.

That way you could create a new user with the old name and this way other users would not run into finding the old disabled user of someone again and again.

We would have to think about how to ensure, that the new username with the same name is not interfering with federated servers, that were offline for a while during the period, the user was disabled, renamed and a new user with the same name created.