As a game ages and the developers iterate on it, they tend to lose touch with the players actually playing it. Changes will come out of left field, or new big expansions will with secret, exciting systems will fall flat at release. Players are left with tons of sunk cost in a game that's now less fun than if the developers did nothing. Players clamor to for the ability to be able to play older versions of the game.
MMOs are different than games like Uncharted or Undertale in a few key ways. They're much less about creating a spectacle / playthrough experience than they are about creating a game that has a high hour-to-hour quality of life. They're games that need to be optimized for playing 10000 hours instead of 40. As players, we want our games to be good worlds to live in. They don't need to be developed in secret.
As such, I propose that the after-launch game iteration process follows a governance system similar to old-school runescape. Why do MMO developers create patches in secret and then launch them without community approval? Is creating exciting and mysterious content and systems more important than creating nearly universally loved systems? Follow a democratic process that ensures that the players are getting what they want, and you won't need unfriendly retention mechanics to keep your players around.
Propose your system ideas, balance ideas, and bugfixes to the community. Get on calls, and make videos. Educate the community. Have the community either elect a council (representative democracy) to vote on proposals or have them vote directly. Develop in the open and your community will love you for it.