However they might have instead used some of the donor money to hire someone to do a clean-room re-implementation of the functionality for which they couldn't get the original author's blessing to change the license of. This might have been the more respectful thing to do perhaps.
If no, then what percentage of contributors need to agree? Or do I need to rewrite all of the code that I get noes for?
The core problem here is not that they are changing the license. It is that it is now not clear what license is actually in effect; and it could very possibly end up being both.
The upside to this is that no one enforces these licenses anyway.
[0] Which might be a bigger deal in other contexts, for a security library, I should be staying up to date anyway.