Btw,
I kept a copy of the old installation. The old one still does not work when I start it, even after verifying files. If you want me to send it to you feel free to tell me where to.
There is a similar crash on PC that crashes the game once you click play on the launcher.
I just confirmed that deleting all game files and downloading everything again fixes that.
(Would've commented that on the original thread since this seems like a slightly different bug but that one was locked)
Edit: I can confirm that deleting Tools/Windows/x64/steam_api64.dll also fixes the issue.
I updated the game and optimized my download cache.
Now when I click play not even the game window pops up, it goes straight into the crash reporter: WAR-3963328
I tried verifying my files and changing some launcher settings but nothing helped.