The Queen Mother never lied to the President.
My understanding is that the President and AAA knew about the Baby King before the late King Oyo died. The real dispute appears to be less about the boy himself and more about the Queen Mother and the question of who controls the palace.
Musuuga may accept the Baby King, but without the Queen Mother. That, perhaps, explains why the shortcut was taken
Baby king exist. The elders look helpless. They look captured as said by the princes.