HB Studios has shown progress from TGC 1, to 2, and now to TGC 2019, so I'm cautiously optimistic that the next iteration will be better. However, since HB Studios has been in a full development cycle now, with their publishing partnership with 2K, they been far less forthcoming with information concerning the direction and future of the franchise.
What's next for the series? I'd guess they'd try to get more mileage out of their PGA TOUR license, and possibly even include a few featured PGA TOUR Pros. If nothing else, I'd expect to see more PGA TOUR licensed courses in the mix. I wish I could give you a better answer, but that's the best I can do with what I've got to go on.