Now, matchmaking will continue to be based on your internal rating even after you run out of bonus stars.
Great, so now ladder rank is totally meaningless.
Your rank is your ladder progression, and is still a good indicator of your skill for most people (just not for bots). And it does still affect your bonus stars for next month. The fact matchmaking switched to a different mode when you ran out of bonus stars used to be a slight upside, but nowadays was just a big downside because it was just "you can now encounter bots" mode.