I don't think Linus is particularly concerned about bcachefs-tools, and whether a particular distributions ships with it or not isn't a concern for the kernel. Presumably though, distributions that don't ship the tools may also want to disable it in the kernel, although I'd imagine they'd leave it alone if it was previously supported.
Linus' complaint was about adding feature work into a supposed minor bug fix, especially because (going from Linus' comments) they were essentially refactors of major systems that impacted other areas of the kernel.
Edit: Reading through the thread, it seems like there is a claim of rigorous but effectively private testing. Without the ability to audit those results easily it’s causing a lot of worry.