In the most believable leak to date, a Redditor has managed to find a screenshot from what appears to be either a Red Dead Redemption Remastered (or sequel). The image was found on a Rockstar employee’s portfolio page along with other artwork that he has previously created for the company.
This is where things get a little murky. The artwork is originally dated from July 2015. The screenshot looks remardkedly better than the original Red Dead Redemption, but probably not good enough to be from a sequel. The issue is that the location doesn’t immediately resonate with any location from the first game.