My main concern related to game companies doing this is they often implement anti-cheat engines that inspect the system and network. This would given them ability to inspect arbitrary TLS traffic if they wanted.https://twitter.com/taviso/status/943943303401160704 …
I'm still finding this confusing, because you've already given them Administrator access. You're saying that they might abuse your trust in future - legitimate concern, but what difference does it make if they add a per-machine certificate today?