The rep fish were used for rep and in recipes prior to Storm Legion as well. I would suggest using the rep fish for rep turn-ins first especially since you should be revered in Eternal and Caretakers from questing/carnage alone. It's about ~720 fish to go from 0 -> 60,000 to hit Glorified. That way once you finish up either rep, you can stockpile the rare fish for recipes (which to be honest are just the feasts and tanking consumables unless there are dimension items but I don't care about those :P).