Not all of the ideas of the Red Dead Redemption 2 developers made it into the release version of the game. During a conversation with Lex Fridman, Rockstar Games co-founder Dan Houser recalled the original vision for the game's prologue.
As it turned out, the authors of Red Dead Redemption 2 were considering a very dark option — Arthur could have been shown as a very repulsive, cold character.
According to the original idea, Arthur was supposed to survive the death of his child
...he wasn't very sympathetic to his girlfriend who had the baby. So at first he looked very, very repulsive, and I was curious to experiment with that, because then his redemption arc would become even more interesting
However, in the end, it was decided to abandon this version of the prologue and, according to Dan Houser, it was the "right decision from a commercial point of view" and that "it was better that way."