First of all, they will hatch. BUT do you really want to introduce all that bad bacteria the cysts are known to harbour?
Brine shrimp should be hatched in separate containers, with the hatching water thrown out after harvesting the nauplii that need to be rinsed before feeding them to your fish. RAISING BRINE SHRIMP
BBS nauplii are pretty nutritious which is why many breeders us them for feeding fish fry. The adult brine, however, are pretty poor overall from a nutritional standpoint. I'm just now weaning my baby banggai's off bbs for dead food.
The nutrition of feeding adult brine to fish can be just as good as any other food. All you have to do is "gut" load them before feeding to the fish.
Want to feed spirulina to fish that don't want to eat it? Just gut load the brine for a couple of hours first, then when the fish eat the brine, they get spirulina.
Selcon and Selco are also excellent gut loading foods for feeding brine shrimp to reef/salt tanks.