Why hide the ranks at the end of match?
Because a lot of people would always complain and/or make assuptions on the players of their team after the match had ended.
Since rank is absolutely meaningless in PvP, they did the right choice.
Also, decent players take less than a minute to understand if they are playing with noobs or not.
As someone who’s been PvPing since beta, I like the change. Ranks were always something that players got angry about when it’s only loosely correlated with MMR in tPVP.
If the matches are unbalanced, that’s a problem with the matchmaking system and MMR, not ranks.
Same as why they removed ping from the loading screen in League. Nothing meaningful is really gained by it, and people are super toxic about it. I’m all for lessening the toxic behavior in sPvP.