In theory, I doubt development would continue. For a federated cohost to survive long term, it would also need to be open source, with a developer community that could fork the project and carry the torch. That's a very different cohost we're envisioning, even excluding required UX changes to make it possible.

At that point, one might as well imagine a cohost that explored better ways to make money, or attracted more users, or ran a tighter ship. Both scenarios lead to this discussion never happening.