> For instance, in Overwatch at the end of the game there are highlights. If you leave the highlights and queue again, you aren't actually in the queue until the highlights play out in your previous game.
That used to be true, but it has not been the case for a couple of years now.
Without knowing the specific details in this case, one of the biggest problem in multiplayer games - even very popular games - is filling the matchmaking pools with players of a similar skill set and region (low ping) to you. My guess is that even though it doesn’t show you queueing, that’s just some entertainment to fill time - the server is actually scheduling games to maximise player counts.
That used to be true, but it has not been the case for a couple of years now.