The point isn't to bring back the frog, the point is to make a proof of concept that we should be cryogenically preserving the genomes and genetic diversity of all Australian animals.
I've been pretty involved in this project (I collect the frogs they use the embryos from, and subsequently get to stand around and watch while the 'real science' happens), and while all these people would love to get fully grown Gastric Brooding Frogs doing this (which is quite possible) they don't have plans for re-introducing the species to the wild. Any suggestion of that would be far in the future.