A rogue actor may create a new distro, maybe for some niche use case such as accessibility or retro gaming. After acquiring enough false (and even some real) users that the Linux Foundation accepts them as a notifiable distro maintainer, this maintainer could then pwn machines before the exploit is made public.
Rather than the current situation, where they can pwn machines after the exploit is made public?
I didn't say all distros should be notified, for that exact reason. I listed a handful of major fistros.