It might be controversial, but I think Twisted Metal would be the perfect fit for a battle royale type game. I'd want it to have a strong single player and local/small scale multiplayer (like the previous ones), but a larger map with the chaos of 100 psychos driving around could be a lot of fun.
Outside of the car though? Maybe some bonus points for how long you can run around without getting popped like a party balloon.
Edit: but we all know this would have been just a shit live service game. So not much lost. Can't believe no indie dev has come out with a good successor.