There is no way MS could claim any dominion over code that has already been distributed with an MIT license, even if all contributors to Qora agreed to change the license at the time of signing on to Azure service.
Whilst I don't doubt that Microsoft would lose any lawsuit over a clone prior to the change of license that certainly doesn't mean that they wouldn't try it and my point was the bug fixes made after the change of license could not be applied to the clones (unless written in a different manner which is another potential lawsuit).
Microsoft (and other such companies) spend many millions per year on lawyers and are always in court and quite simply CIYAM does not have the funds to be involved in any lawsuit with the likes of them.
Personally I would hope that the Qora team come up with the funds to retain ownership of the IP if they decide to go down this path.
Agreed If we end up joining the M$ program...then we should crowdfund and pay to join...