Reduce the challenge for win 2 ranked games to win 1 ranked game. On average it probably takes most people 2-3 games to win a ranked game since I see alot or people including myself with less than 50% win rates. It takes forever to find a ranked match at this point regardless of the playlist. I dont ever play ranked or go for that challenge these days because I know even if I win my first game I could play for another hour or two without getting a win due to wait times. If they reduced the challenge to win 1 ranked game more people might feel like they can complete the challenge in a timely manner and the ranked playlist could see a population boost.
The alternative theory is less people would play ranked after they got the 1 win instead of them playing more matches to get 2 wins. Which I dont think is true because I think most people playing MCC ranked play it almost every day just for fun. Making the challenge 1 win could draw in a few of the players who play once or twice a week or less