I cannot see the opponent’s rank in game neither on PC or mobile devices. Is there a new setting which I can turn off and on that is now off by default? Would be nice to see the rank of the opponent again.
Do not know why, but up it doesn’t show your opponent’s ranks right up until legend.
It’s probably because they changed the matchmaking system. You are now matched with players who have your mmr, instead of rank. It would be weird if you as a Gold 3 would be matched with, say, a Copper 9.
An option would be to show players’ mmrs, but I think there are many reasons why Blizzard would not want to do that.
What is a mmr ? What is a mmr? Asked twice for the 20 char limit 
MMR stands for Matchmaking Rating, its a number you cant directly see, but the better your rank the higher your MMR.