They’ll recant after their usage drops to a fraction. This move makes zero sense no matter how you look at it. As a generalist distro it’s too early to drop X.
If they want to become a niche distro whose only claim to fame is “we only pack Plasma 6”, big whoop, like there’s any shortage of that. What kind of distro defines itself by what it does not offer? And is that the kind of distro that Fedora aims to be?