> or if you managed to get permission from every single person who contributed
This makes it sound more difficult than it actually is (logistically); it's not uncommon for major projects to require contributors to sign a CLA before accepting PRs.
That depends on how old and big is the project. For example Linux is "stuck" on GPL2 and even if they wanted to move to something else it wouldn't be feasible to get permission from all the people involved. Some contributors passed away making it even more difficult.
Even if they wanted to move to another license (which they don't), they wouldn't be able to do. So sounds exactly like they're "stuck", regardless of what they want.
How is the problem of "you signed a CLA without authorization by your employer to do so" solved? I'm mostly asking because I saw the following:
"I will not expose people taping out Hazard3 to the possibility of your employer chasing you for your contribution by harassing them legally. A contribution agreement does not solve this, because you may sign it without the legal capability to do so (...)"
This makes it sound more difficult than it actually is (logistically); it's not uncommon for major projects to require contributors to sign a CLA before accepting PRs.