Players can make offers and devs can say "yes" or "no" to it, also devs then developing story further should pay attention to what is happening in player base. Players can change the storyline. Not much, but enought to feel important. Major changes requires a lot of time and efforts. It changes slowly so people get used to it anyway.
Also. Ability to take over bases and such will drive disco in more pvp oranties clan fighting game. I suggest to think before you offer such nonsense. It just proves that community approval in some cases in very incompetent on deciding storyline turns and such.