Whilst I agree that it’s unlikely that it was an RCE in EAC like it’s been floating around, nothing can be entirely discarded yet.
I do agree that it’s likely safe to play Halo, if the hack happened due to calls made from Apex to EAC, that means EAC’s APIs made it possible (still unlikely to be an RCE though). With that in mind, bugs or malicious code in any game that interacts with the EAC APIs could cause the same issue.
This is one of the dangers of kernel-level anti-cheat systems.
It should be safe® on Linux though, as it has no direct access to the kernel.