I understand why they wouldn’t want to suddenly change the branding of existing projects though.

I’m not sure if I agree, I feel like the long term damage of keeping the names is greater than changing them now to Fedora Plasma Atomic (Formerly Kinoite) / Fedora Atomic Workstation (Formerly Silverblue). Leaving them as is, is just going to create more confusion in the future to new users who won’t immediately understand why the naming convention is different for the other spins and will create more confusion for documentation / support threads online.