From the GitHub thread it seems like these projects willingly transferred the copyright to the DNF when they joined; is that not the case? If it is what grounds do they have for being upset?
What's being done here is changes to how the project is managed. Basically inserting an upper management over the heads of existing maintainers. AFAIK, this right was not given (or at least the maintainers did not intend to give) to the umbrella org.
The new owner can do further on how he pleases.
Sad in this case(es) but from a legal standpoint it's very likely like that, I guess (INAL).
This is a cooperate thinking applied to a foundation. Is a recipe for failure.
But the argument is about whether the .NET Foundation could do such a thing. The argument is whether they should. And, the .NET Foundation chooses that they should take over the projects, project maintainers can make different decisions themselves.
None of this has been decided yet.
I used the key to steal your car.
Isn't a better analogy that they willingly gifted away their garage with everything in it under a _promise_ that they can still use the car?
Honestly, to me the only way out seems to exercise the licensee rights and fork.