I wouldn't think freeze dried fish would affect the quality of th ewhitebait, it may lock nutrients in for all I know.
some fish stores sell freeze dried shrimp and worms for fish, so im sure slight freeze drying wont hurt.
however I have noticed fresh foods are eaten teice as quick as thawed frozen food.
for example my ray pups at the moment only eat fresh salmon and wont even look at defrosted salmon - clever little flyin cds.