[Gormo]

"No takebacks" is already inherent to the nature of all FOSS licenses. No one, not even a "supermajority quorum", can retroactively change the license to code they don't own the copyright to, and each contributor retains ownership of the copyright to whatever code they've written, individuall.

The only exception to this is when corporate-backed projects sometimes insist that contributors assign copyright before accepting their contributions -- not sure if that's what's going on here, though.

What does happen with MIT or BSD projects is that since these licenses are not "viral" (in the sense that they do not require modifications or derivative works to be released under the same license), and because contributors do own the copyright to their own code, anyone can take an MIT/BSD project, and modify it or build their own work on top of it, then release their own version under a different license applicable to their work.

But that doesn't retroactively change the license for anything that was already BSD/MIT, it just produces a new work that mixes BSD/MIT-licensed code that was already out there with new code that is under a different license.

So no one can ever "take back" anything that already existed: they can only control their own subsequent work built on top of it.