I know that fans would love to learn of Jack’s story and this would indeed keep the Marston legacy alive, yet keeping to historical accuracy as much as Rockstar attempts to, it wouldn’t be the Western we've experienced in the previous two games. Outlaws are replaced by inner city mafias, there are more cars and concrete structures than horses and shanty sheriff towns.
The Western era was already dying out during Rdr2 in 1899, 15 to 20 years on and it’s certainly dead and buried. We begin to stroll into L.A. Noire territory or even more GTA than RDR where I’m sure riding around in cars would have to be an option they couldn’t refuse us. I’m sure they could pull it off and I’m confident they’d develop a great game only, no longer one of bandits and stagecoach robberies. No longer the classic Western gunslinger world of which has always been the Red Dead theme.
On the other hand, they could continue going further back in time telling the story of the younger days of the gang, or perhaps even keeping to the same generation as Rdr2 yet with completely different characters.
The issue here becomes a gameplay one.
Rdr2 did such a fine job of portraying the era with its guns, towns, beautifully crafted climates, way of life etc, that it doesn’t feel as though they could add a great deal more to raise the bar to greater heights. Would we be in for more of the same?
The limited modes of transport (horse), similar/same weaponry, all too familiar environments, robberies and small town bank jobs that we’d have seen before?
It’s difficult to figure how they could bring us a game that wouldn't feel too much like it’s predecessor yet stays as true as possible to history.
GTA on the other hand doesn't have this problem, it could explore a number of different eras and locations across the globe if Rockstar fancied it, it’s not locked into one place and time with such limitations.
There may never be an RDR3 or if so then not for many years I’m sure. It’s interesting to consider the possibilities though.
Where could they take it considering gameplay and theme? Could one of those two be compromised to suit the other?