Just an idea, that I thought of after a match I had last night with BloodThirstyLord.
He had been waiting for 40 minutes to get a game, and ended up in a dead lobby with a single friend of mine.
That friend then invited me, and I then invited 2 others, and we were able to start the game. Without this, they would have had to quit and remake, and all that waiting would have been for nothing. (Which is often the case these days).
The Idea
After the wait timer has exceeded the “estimated time” (or sooner), place the player into the lobby screen.
This will allowing them to invite friends into the empty spots, with the possibility of progressing the game.
Now I understand this only helps players with friends online at the time, but I can’t see any downside to this. If there is one for some reason, you could always just give the player the prompt as to whether they want to connect to an empty lobby.
Note: Matchmaking should still ‘continue’ looking for players in the lobby. It’s just to give you the option to invite people first, just as anyone can invite once in a lobby.