Somehow I don't expect HP to be very successful project as well, but the reasoning seems off to me. If anything, Japanese market is more open to new HP franchis

Somehow I don't expect HP to be very successful project as well, but the reasoning seems off to me. If anything, Japanese market is more open to new HP franchise products than the others. But I don't think it was actually the Pokemon that made the game successful, it was the mere fact of neutral, yet well-known setting in combination with a relatively novel gameplay. Ingress attracted attention as it was, but lacked the familiar name. But essentially Pokemon Go is the same thing as Ingress, and HP will probably be too. It doesn't seem to be as attractive as that combination of novelty and nostalgia of Pokemon Go 5 years ago. This isn't even remotely a reason for why the game should fail of course, merely absence of an obvious reason for it to succeed. But IMO: while having absolutely huge potential to be great, neither Ingress nor Pokemon Go turned out to be a particularly good game. Maybe HP will be different, but for now I stand by the opinion that Niantic actually isn't a great game-making company.