I don’t think it’s working, I just tried it on supremacy and the era never changes, so for example if the first match I get sent to is geonosis, every map after that will be age of the republic until I quit back to the menu. If I start on Hoth, every map after that is age of rebellion. I was hoping the eras would change after each round.
Which platform are you on? and did you try during peak or off-peak hours? Matchmaking also tries to put you at the beginning of a match with the maximum number of players. Unfortunately, what that means at the end of a supremacy game is that if 30+ people are looking for a new game, you will more often than not find the same game as them which is why it seems to stick to the same map rotation I'm afraid.