I'm not in New Zealand currently to talk directly to the team in person, but there is a discussion about this going on and I wouldn't be surprised to see a tweak to map drops in the immediate future.
One ongoing issue that we will need to solve is that each league has varying mechanics that drop maps, and combined with the (often changing over time) base map drop rate, can occasionally cause leagues where they're slightly too common or slightly too rare. Both outcomes are bad for player experience because map drops are quite a sensitive equilibrium. While our pre-launch simulations can take into account the base map drop rate, we certainly need to put some work into more accurately factoring in the league-specific sources of maps so that there isn't a noticeable difference in the difficulty of sustaining maps from one league to the next.