A team survives losing the Mac that runs it
If the Mac that runs a team is gone for good, any member can start the team again. Everyone is invited back, with the same channels.
One Mac in each team adds people and applies team changes. If that Mac was lost, the team was stuck and nobody could add anyone.
Now any member can start the team again from the team page. The new team keeps the name and channels, and every member sees an offer to join it. Nobody is moved without saying yes, and the old messages stay readable.