According to the Rockstar Games rumor mill, the next game from the developers of Red Dead Redemption and Grand Theft Auto is not Bully 2 or GTA 6, rather it's a brand new IP and open-world game set in the Medieval era. According to the rumor, the source they received this information from has been correct about GTA Online and Red Dead Redemption 2 information in the past. In other words, there's reason to believe they are credible and trustworthy. That said, the rumor alleges this open-world Medieval game will be released sometime Q1 2021, or at least that's what Rockstar Games is internally aiming for. Further, an announcement is reportedly not very far away.
Unfortunately, this is where the salient details dry up, and the only other thing mentioned is that the game will have swordsmanship and dueling, which makes sense if it's set during the Medieval era, presumably somewhere in western Europe.
Of course, this rumor should be taken with a massive grain of salt. Not only does the source have no history, but everyone and their brother's mother's dog claims to know what Rockstar Games is working on. That said, what's interesting about this claim is that it isn't the first time a rumor has popped up claiming this. There's been a few different isolated instances where, seemingly out of the blue, a rumor has popped up claiming Rockstar Games is working on a Medieval game. Of course, it's possible these rumors are simply piggybacking on each other, but it seems unlikely given the varied locations they've popped on. Still, reserve the biggest grain of salt you can find, because there's a much better chance this isn't factual than being an actual scoop. Though, I've seen more shoddy, suspicious, and doubtful rumors turn out true in the past, so anything is possible I suppose.
Anyway, at the moment of publishing, the safe bet is that Rockstar Games' next title will be a new installment in Grand Theft Auto. Meanwhile, there have been plenty of rumors and reports suggesting a Bully sequel is actually Rockstar's next game, but for now, if I was a betting man, I'd wager on GTA 6 being the next game out of the industry-leading developer.