Once a project is donated to CNCF, it is donated in full. You cannot withdraw. They would need to withdraw from the project, but they cannot withdraw the project itself.
I guess the answer may be that they can ask the CNCF to archive them, but the CNCF/Linux Foundation technically controls the domain and trademarks. So I guess they would need the CNCF to release those back to the project if they wanted to withdraw or move to another foundation. Interesting.
> Trademarks and domain names of archived projects are still hosted by the CNCF and the Linux Foundation
> The project is free continue development in its repositories, ideally with a goal to reactivate itself
Correct, once the project is donated to CNCF, so is the trademark. Even if CNCF votes to archive the project, the trademark is still owned by them. I haven't seen an instance where CNCF released them.