in previous interviews he’s pretty much said in the past that outside the Kernel he has no clue what’s going on as far as the entire Linux ecosystem. I watched an interview from awhile back where he didn’t even know what NixOS was. Time and time again he’s said all he really does now is read emails and compile the kernel to check for bugs. I believe he only uses Fedora, doesn’t like Debian and thus isn’t a fan of Ubuntu either. in an interview from a few years ago he said the only reason he prefers Ubuntu over Debian is it makes Debian “usable”. He pretty much always states he prefers a distro that allows him to easily work on the Kernel (that’s all he cares about) and so he uses Fedora.