The way I see the root kit anticheat situation is that because Valve has their own Linux based OS, these companies making anticheat are probably going to end up tailoring it to whatever kernel Valve (or whatever the biggest/most widely used distro made by a large game corporation) uses to ensure people aren't cheating.

With a kernel that can be swapped out for another with varying degrees of difficulty, why wouldn't they just tailor their work to whatever the biggest corporate game company supporter of Linux is using? If SteamOS (or any other distro made by maybe someone like EA, heaven forbid) ends up becoming what these anticheat devs see as the defacto Linux distro for gaming, I guarantee they'll probably just focus all their efforts on making sure SteamOS (or whatever it ends up being) works as best they can and hanging out everyone else to dry.

A real "Wanna run the latest CoD (or something similar) on your device? Make sure you use the kernel we say you have to use!" kinda situation is what I foresee happening.

There's also an OpenBSD song with a few lines of lyrics that I think could sum up what could (and sadly most likely will) happen, in metaphorical Odyssey kind of way:

Corporate monsters, many closing passages\ Tempting harpies\ 13 years of treachery

Though it's definitely going to be more than 13 years.