To avoid losing momentum on the new players you need to IMMEDIATELY introduce skill based matchmaking to the best of your ability or all these new players from F2P will get destroyed and immediately just quit.
All these things fall on deaf ears unfortunately though. If this mechanism is introduced FAST (ie not a year from now, I’m talking January) then you MIGHT get lucky and keep a good number of these new players and then be able To leverage back map selection and more.