I’ve honestly wondered this as well. I’d assume if more freshwater species get added that are harder to breed, and if there is a big enough demand along with stores willing to stock a saltwater variant - it may be possible. Although I wouldn’t really count on it since I feel like those who buy them and their glofish tanks (which are painfully small and overpriced), probably won’t pay double what a saltwater fish is for the GloFish aspect added to it.

I think the issue with saltwater fish already being not that commercially great yet, and the fact that many species are picked from the ocean still - it would look horrible to add the colorations to some and then having to teach people on how to handle saltwater in general when it’s not as close to being easy like freshwater is.

its too hard with marine fish since many are from the sea. one day sure if they can breed them inside of tanks, otherwise never.