Unless he names a worthy heir… actually no, even if he does, kernel development will almost certainly fork into various factions who will grow, wither and die, taking inspiration and code from the others like entire distros and other software projects currently already do.

We can only hope that a handful of those continue to carry the torch sufficiently well and that we don’t all end up relying on some corporation’s stock kernel.

I assume that the kernel and related development is sufficiently well licensed and legally protected that even if that happens, they’d continue to have to release the source code, but it’s still something I’d prefer not to happen.