The increase in pitch, as well as producing lift to make the blades cone up, has a far greater effect on increasing drag, slowing the blades down. No correlator, revs will drop. No conservation going on here.
The correlator adds fuel to the system in a coarse manner, and the RRPM go up because it is a bit too effective.
The coning-causing-RPM-increase really only is apparent when flaring, or in auto.