The hints to me Point as much if not even more towards Rome or even something new as I don't think Johan have ever been that strongly involved in the Victoria series, although I could be wrong about that.
Wrong you are, indeed. I read somewhere Johan himself specifically stating that he was responsible for most of the code behind Vic2 POP system. Considering that POP is pretty much the core of the game, it's fair to say that he was involved enough in the project. Moreover, when he says "I've been with this project from day #1", that doesn't really say anything since he is the global mastermind behind all Paradox's projects. Of course he's supervising everything that's made in the studio from the very start to the very end. At least I wouldn't expect less from him.
He also once stated that he would like to "kill the global market with a sharp axe". So, for good or ill, he definitely has a specific point of view about designing the next Victoria installment.
As for gathering all the hints so far, to be fair, the vocabulary used for the first and third teasers really points toward Victoria more than anything else, while the actual meaning of the words employed could just as much points toward Rome 2. "Popular demand", while obviously refering to POPs and a very famous Vic2 mod, also reminds me of a very famous quote from random roman source that I know only in french : "Que demande le peuple ? Du pain et des jeux." (What does the people demand ? Bread and games). "Minorities" could also refer to the persecution of Christians under roman law, for example.
The main point of contention to me is the fact that Johan is considered game director and designer on this project. I would have expected King to be THE game director on a sequel to Victoria. And we all know he
is game director at Paradox studio currently.
So... Right now, as others have thought before me, I'm actually figuring a reboot of the Victoria franchise, with a different name, and a bit different scope. I don't think Victoria is that popular outside of die-hard PDX fans anyway, and all of them will know about this new game whatever its name and theme. So maybe the marketing department has come with an evil plan to conquer new markets after all...