If I were designing the matchmaking logic, I would do what the title says. The whole point of Warzone is the REQ system, so to allow people to join a game and be shut out from it is a failure to deliver on your requirements. If the REQ service is too unreliable, then fix it instead of side-stepping the issue. Additionally, any player leaving a game who does not have a REQ service connection should not be penalized.
Good idea op, It seems like they could implement that.
Hard reset your xbox. If the game loads without sync errors, wait a couple of minutes for the req system to load. You can tell it loaded because you will have access to your req inventory and the req store. If you get an error message, when you access the req store or inventory, go back to the main menu, and wait another 30 seconds. It takes time but it does load. If it does not load within 5 minutes, you will have to restart the game.