Ghost shrimp are more aggressive than RCS or other dwarf shrimp as their claws grow to be much larger. When I kept ghost shrimp with RCS I saw a ghost shrimp eating a RCS twice, before I took out all the ghost shrimp. I am sure they will snack on a fry that gets too close to them.
RCS are will eat algae and eat dying parts of plants, as well as left over food. If you keep RCS with your fish, your fry will definitely be safe. However, the baby shrimp will not. But with enough hiding places the RCS will still be able to outbreed the predatation.