i am playing this game for over year and half and have never seen that devs surveyed players. most of the other games that i have played that were in development had surveys at least about current state of the game, if not about its future directions.
first question that needs to be answered is popularity of modes. and based on that removing them from the game or tweaking their chance of appearing in MM.
second question that needs to be answered is worst map/maps in game that need rework.
third is about most annoying things in game
etc.
overall it would be good if devs made survey so they get feedback about area where they should focus their time for best players satisfaction. i would guess that some things could be easily done and make many players happier with the game.
I was able to survey over 150 people from this forum and reddit, so I would consider the survey itself a success. The sample size is not big enough to draw any major conclusions, but I think the top and bottom results of the survey are generally reflective of what the community wanted at the time.