Nobody ships vanilla kernels. Sure the reference implementation was unaffected but users never experience vanilla Linux kernels
You know it's not that hard to debunk this:
> You'll then be left with a kernel-6.X.? directory, containing both an unpatched 'vanilla-6.X.?' dir, and a linux-6.X.?-noarch hardlinked dir which has the Fedora patches applied. [1]
WOW fedora patches! Sounds to me like they're not shipping vanilla.
I have problem with backaptching 10s of thousands of changes to years old kernels by people who don't really understand the changes or consequences, like 5.4, 5.15, 6.1 or whatever. Not patching up 6.6 or 6.7 kernel with a few out of tree patches, where they mostly understand what they're doing and can test the limited set of changes they're applying.
Anybody who cares that much is very likely already compiling their own kernels (I speak for myself here). It doesn't make sense for distros to do the extra work to support it.
Just expanding on this a bit: my Debian laptop has a Kconfig with modules disabled that only includes the exact set of drivers it needs. It takes ten minutes to rebuild on the laptop when I pull from git. Even if Debian did all the work to let me automatically install the latest vanilla kernel... I'd still build it myself.