They said "provably", not "probably", so the good news is we all already agree :)

You don't even need to go back to the early 2000s Bertelsman-Sony copy protection scandal.

Millions of people install rootkits on their PCs today in the form of anti-cheat software that has a greater level of system access than Bertelsman/Sony ever had.

Ring 0 level kernel access. Code that can be executed with above admin level privileges and do anything it wants to with your system. Shit, it could reflash firmware on your PC if it wanted to, allowing malicious code to survive OS reinstalls.

And not only that - it's not even effective as an anti-cheat solution, leading to the question of why they bother with it anyway? Data harvesting? Security theatre?