[coldpie]

Not really. If your changes aren't controversial, you don't really need to get permission. Arguably some developer could demand their contributions are reverted, or sue, or whatever, but for all practical purposes no one will care enough.

Having an agreement isn't a no-cost option, it adds another barrier to contribution to a project.

[Argorak]

Controversy isn't part of the equation here.

You change from license A to license B to your project without asking permission of those that contributed under license A. Some party uses the code under B and violates B, but not A. Their attorney argues that you didn't have permission to re-license from all contributors, so the switch wasn't possible. You try to contact all developers that committed under A. Sadly, one of them died a year ago. To add a problem, that person lived in a legislation where you cannot give away authorship.

Suddenly, you are in a legal mess. You can choose to follow through or drop the case.

[forgottenpass]

spindritf said "make any changes"

coldpie seemed to assume s/he meant "any changes", not "any changes to the license"

[Argorak]

But the initial part of the thread is about a CLA and a CLA covers the licensing part of the business.