To be honest: i really don't know

I believe it would make everyone happy (me included), BUT the expectations would also probably be set extremely high by the fans

If it was a prequel to RDR2, maybe, since there are some things we know happened and didn't get to see, but it would be unnecessary at best

But if it took place after RDR1 then definitely not

I think it will be the founding of Dutches gang or after but before RDR 2 and we’ll play as Mac or Davey Callender or both. Then it could end with the Blackwater Massacre.

You could maybe play as sean, and the final mission is the blackwater massacre. The 100% cutscene should be Sean captured by the bounty hunters

If there is, it should not be part of the Redemption saga. That story is over.

For what the next game should be, I have two ideas. One would have you playing as an outlaw in a gang, without any of the "morality" of Dutch's gang. The other would have you playing as a lawman trying to bring law and order to a lawless, frontier town.