I got this rather than seeing my opponent pre-match screen (I did hear the intro voice lines for their character though).
Got the same bug, just seems to happen if Quick Match finds an opponent during Survival. When I left the queue it also had some oddness where it remembered how many opponents I had left to fight but the round win circles acted as if I was at the beginning. This meant that the orange “boss” circle got filled in by beating a regular opponent some time after beating the Shadow Boss for that set of 5 because the Shadow Boss came “early.”
This is fixed for next patch.