I just wanted to post something because we need to keep this freaking thread alive if we want an actual fix for this from Blizzard. It is SO frustrating.
I did some digging and this thread here helped me a little bit for us PC gamers.
(Note: I did methods 1 & 2)
" Fix Antimalware Service Executable High CPU Usage on Windows (2022 Guide)" BY NORBERT WEBB, FEBRUARY 1, 2021
It is basically how to get your antimalware to stop working as hard so Blizzard can run OW2 but it is ridiculous that we have to go to these lengths just to get the game to load. It has ever been since the launch of OW2. However if you guys do get stuck you can run your task manager and find the Overwatch Application to end the task and at least try troubleshooting it.