How to shoot yourself in the foot with good worldbuilding: two methods
Sometimes, in the course of telling one story, you make changes to the imagined world you’re creating that opens up the possibility of telling a much more interesting story. This story can’t be told without moving focus away from the characters you’re currently involved with. No matter; there’s no way that these main characters are more interesting to your reader than they are to you, and if there’s demand for them, you can explore what’s going on with them later.
Always tell the most interesting story going on in your world.
Sometimes, you are telling the most interesting story going on in your world, but readers are losing interest: a formerly rabidly creative fandom has stopped writing fanfiction, complaining that the new installments feel hollow. You told the most interesting story in your world, but you limited your world so that the story you were telling was the only interesting story to be told.
Always make sure that someone smarter than you can tell a more interesting story in your world than you can imagine.