Well someone said something about stutter occuring because of the CPU hitch, that’s why I brought it up. The GPU can’t render a frame until the main thread of the game tells it to.
The only other thing I can think, off the top of my head, is that they are running a bunch of new, but inefficient, anti-cheat/hack loops at a low level. That or something is clashing with the Win10 control flow guard stuff.
EDIT: It doesn’t look like it uses CFG, but it uses HIGHENTROPYVA, which means it uses the ASLR features, which are for randomizing memory addresses. I don’t know if the previous version of the WoW client had it enabled though, so I can’t really compare.