No, this was already timed disclosure. This is very common and widely accepted. 90+30 is what Google Project Zero uses, for example. The security researcher has met their ethical requirements already. This is entirely on the kernel's security team for failure to communicate downstream. That is their responsibility.

The thing is, malicous actors are already monitoring most major projects and doing either source analysis or binary analysis to figure out if changes were made to patch a vulnerability. So, as soon as you actually patch, you really need to disclose because all you're doing by not disclosing the vulnerability is handing the bad actors a free go. The black hats already know. You need to tell the white hats, too, so they can patch.