From what I read court seems to ignore GPL license in this perspective, and totally based decision on copyright law.
In short: The license only governs the rights you give others relating to what you own. You cannot give (or revoke) a license for things you do not own.
Edit: I mean even there is minimal contribution left from Linus in kernel, if he was the plaintiff here, would result be different?
He still cannot claim copyright ownership of the whole though, since he did not create everything in the kernel. Commits from other authors still have their own copyright.
It's Free Software. As long as you adhere to the GPL2, you don't need to take Linus' will in consideration. It's nice if you do, but he can't take back the licence. If he could, it wouldn't be Free Software.