I think the only reason I noticed is that they’ve been “fixed” in the past.
If the enemy is going to kill you on it’s turn, you can’t pause and just exit the match anymore.
In a wave mode, if Thanos kills everyone with his Death power, it will show the same character get killed and then show up for the next match. So if he’s facing 3 soldiers, the last might appear as, say, Luke Cage, the characters are downed, and Luke Cage pops up again for the next round.
Again, absolutely low/no priority, but I remembered they’d been fixed before.
This isn’t just Thanos. Any time you down multiple characters in a wave that has enough remaining characters coming in, it happens. I see it all the time in The Big Enchilada when I get cascades with 5* Professor X.