They will eventually. If I had to guess, it will be in 5.0. There currently isn't anyway to get an extra Gig as the only one available in the game is the quest; and if they made a craftable Gig, they would need to give it stats in order to make it viable (+GP is meh right now as most maxed out fishers have plenty of GP), which means they would need to re-balance fish requirements.

It may come sooner than 5.0, but that's where I'm looking for it to happen.