NA XBox is merged with EU XBox. The population size is closer in comparison to EU PS/PC. XB is not merged with PS/PC because of either a decision made by Sony, Microsoft or both.
Not good enough for really fast queues or random queues on old instances, but enough for you to play the game. Its not merged because sony or microsoft dont want to
Id welcome you over, doubt the gatekeepers would without complaining, its not like the devs would do it without having a system in place. Dont take these guys to serious, its rare to see a positive comment out of them.
Theirs A LOT DB can do, but notice what stands in the way of progress on that from is the very community themselves