They've already released an official statement saying that they would have liked to add additional servers for this but due to the global superconductor shortage, they couldn't procure the necessary equipment. This is only the first weekend. It will lighten up as people progress farther/the newness dies down some. The huge influx of players from other games in addition to returning players that haven't played since they finished the last Shadowbringers patch also account for a large part of the queue.