It looks like an official Rockstar source is pointing towards Red Dead Redemption 2 making it to PC at some point. This comes from the game's companion app, which contains code that references a PC version. It might not be the most definitive confirmation, but it's enough to give fans hope.
Obviously the presence of 'PC' can only mean so many things. Especially the actual use of the phrase 'PcVersion.' Also of note is the Oculus parameter, which suggests the ability to work with custom graphics options. Adding to that are other graphics options seen in the app files, such as temporal anti-aliasing, resolution of water reflections, and shadow quality. Graphics options, at least on that level, are really a PC only thing.
All that being said, PC Gamer does offer an alternative explanation to keep our hopes from getting too grand. One part of the files reads 'SIGNIN_PC_APP_URL.' This suggests that the PC files could just be in reference to a desktop version of the companion app, not a full-on PC release of Red Dead Redemption 2.
In the end, nothing is confirmed, though there is plenty of reason to follow the story and see what comes from more digging. Even without the companion app, it only makes sense business-wise for Rockstar to eventually port Red Dead Redemption 2 over to PC.
For the time being, you might benefit from checking out the Red Dead Redemption 2 PS4 bundle. It runs at the standard price of a PS4, basically giving you the game for free. And since PlayStation has had a really great year, there are tons of other games worth playing after you exit the Wild West.
Red Dead Redemption 2 is currently available for PlayStation 4 and Xbox One, but sadly not PC. Read our review of the game to learn more about how Rockstar pulled off its incredibly detailed open world.