I queued for the event and left after 1 minute of the match. I then queued again and was able to join someone’s match who was alone and half way through a match. So I should have been joined the first time I queued.
Second time this happened, I queued for the event, and waited in the lobby for people to join. A guy joined after 10 minutes and said that he had queued twice in the last 2 mins and it had made him host both times.