Linus' message is a bit vague, and could be interpreted as Linus wants to find someone else that Kent can report to as an intermediary, one which will stop any features from getting into the kernel during RC window.

That said, I really don't understand why Kent decides to take a stand on the hills he does. In this case he already helped one user out-of-tree, so presumably they compiled a custom kernel. Sure it's a bit more work to help others with the same if they also have that issue, but not insurmountable. Alternatively users could just wait a few weeks or restore from backup. It's an experimental file system after all.

Instead he decides this is the hill he wants to die on. After just getting back from a timeout for doing exactly the same thing...