Patch 7.2.5 hotfix5 build 24742 was released to Live on Aug 3, 2017 and skipped the PTR since it now hosts Patch 7.3.
Blizzard acknowledged a problem with loading screens on Intel GPU on Mac OS X.
^ Rommax 2017-03-29. 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.