The nuance is a little bit more complex. Let's say I run an AGPL+CC project:

- I become a licensee of code under AGPL if I bring in AGPL code from an external project. Downstream can remove my clause.

- I don't become a licensee if I have an adequately strong CLA in place, and only accept contributions under the CLA.

- I become a licensee of the code if you make a PR to my project without a CLA. However, you're contributing code under AGPL+CC. Downstream cannot remove my clause.

That's my read on both the court ruling and the intent of the AGPL.

It'd be crazy for a court to rule that you can't modify a license. Once you have AGPL+CC, that's a new license (and it's not open source or compatible with most other sharealike licenses).