Patch 7.3.2 hotfix2 build 25455 was released to Live and the PTR on November 7, 2017.
Blizzard previously acknowledged a problem with loading screens on Intel GPU on Mac OS X.
^ Rommax 2017-03-29. #39 Load screens seem graphically glitches now :(. Official Mac Technical Support forum (US). Glitchy looking loading screens on Intel GPUs is a known issue. We're working on a fix. For the time being, it should be a benign issue. It only affects the appearance loading screens.