Does not seem legit. And I've lived through quite a lot of these "leaks" through the years. I mean Jesus, I remember the supposed 3D Symphony of the Night remake for Dreamcast... You kind of develop a sense for these things.
I think people give /v/ some weight ever since they leaked Bloodborne years ago. I believe that was the same place that leaked who was making Bloodstained before it was announced, including posting the "Ritual of the Night" subtitle it had.
That said, we've had a long-running rumor Konami was making an all new Castlevania game and a collection was being made alongside it. If I recall however, the rumor said it was a Switch game, the one platform not named in this apparent leak.