The hero of the first Red Dead Redemption, John Marston, evidently will make an appearance in the sequel. Although Red Dead Redemption 2 is being treated like a follow-up to the 2010 smash hit, the game will technically be a prequel. Red Dead Redemption 2 will take place years before the setting of the first game. It'll explore the inner workings of Dutch Van der Linde's gang, who was the primary antagonist of the first game.
With the prequel setting and the known involvement of John Marston in Dutch's gang it was assumed (or at least hoped) by many fans that John would appear. Yet it wasn't until the most recent trailer for Red Dead Redemption 2 that John's appearance was confirmed. John appears in a blink-and-you'll-miss-it moment during the third trailer for Red Dead Redemption 2, but the beloved character will be involved in the story in some small fashion.
The young John Marston appears around the 1:40 mark of the trailer. In the very brief glimpse, it looks like John has been captured by a rival gang. He is being used as leverage to "negotiate" with Dutch and his cronies. The updated graphics and the notably younger appearance of John don't make him immediately recognizable. Yet the character in the trailer is almost unquestionably John Marston.
One of the defining characteristics of John in the first game are his facial scars. In the trailer, the kidnapped cowboy can be seen sporting wounds that line up directly with the scars that John has in the first game. The wounds are very new, and the stitches are noticeably visible. Whether the cuts John suffered are from his kidnapping by the rival gang or some other incident entirely, the trailer suggests that Red Dead Redemption 2 will tell the story about how John Marston got his scars.
However, fans probably shouldn't expect too much John Marston. John's brief appearance in the trailer is likely emblematic of his appearance in the full game. John hasn't featured in any of the previous trailers and for very good reason. Red Dead Redemption 2 might have multiple playable characters like Grand Theft Auto V but the main hero in all the previous trailers has been the much more grizzled and ruthless character (compared to John Marston) Arthur Morgan. Based on the time period of Red Dead Redemption 2, John will be an underling of the gang, at best.
In addition, John Marston's voice actor Rob Wiethoff has more or less retired from the video game industry (via Polygon). John Marston was Wiethoff's first major voice acting role and his last. He didn't have much interest in continuing to act after the release of Red Dead Redemption and its expansion, Undead Nightmare.
Red Dead Redemption 2 could always recast the role, which would make sense as John is several decades younger. However, considering how iconic Wiethoff's performance was to the character that seems unlikely. A John Marston who doesn't sound like John Marston wouldn't be the most popular move. John will probably be little more than a cameo, a treat for the many fans of the first Red Dead Redemption.
Of course the appearance of John in the trailer could be nothing more than a masterful trolling job by Rockstar Games. Fans are hungry for more information about John Marston. Throwing in a character who could be him in the trailer would stir up even more hype about the game. The character isn't named at all and doesn't even speak, outside a grunt as he's forced to the ground. The wounds are truly the only identifying feature linking him to John Marston.
It would a huge disappointment for John Marston to not appear in Red Dead Redemption 2 but it's definitely possible.
Source: Rockstar Games