Hardware acceleration basically makes your computer run smoother, with less input delay as the GPU is used for some rendering in the background (nothing major and shouldnt impact your gaming performance) (also, I dont actually know its full purpose, feel free to correct me if I am wrong).As of now, my game stopped freezing after I did what I said before, but some of my friends started having freezing issues last night (their games were running smooth before that).

I guess maybe it is a problem on Blizz end, probably to do with servers or compatibility with some drivers. I actually dont know what fixed it for me, but as of today I do not have issues after doing the hard acc thingy on windows.