99% of the users won’t ever see the file since ./discourse-setup hides all the complexity.
The users going to the file, and reading a commented line, researching the alternative values of the key, and opting into a different one, while managing to ignore the various warnings in Meta are difficult ones.
We could just hide the key from that commented line, making it harder to shoot yourself in the foot.
My point is that the commented line currently doesn’t give them any guidance and the knee-jerk for someone who does know what a branch is things “All I know is that my bosses want things to be stable.”
Whether to remove any hint of how to change branches or give them a stronger hint not to change it without learning a bit more is a fine question.