Same scenario as the Uchiha. The Hyuuga clan was left to its own devices and was allowed to do whatever.
What if they decided to rebel against the Leaf village. Apparently there were no Hyuuga clan Anbu ninja and there would be no one to tell the Hokage. The seal on the forehead of the branch clan would activate if they tried to tell a Hyuuga secret.
Would their coup de tat be a success or naw?