Castlevania is a series where, if you try something in 3D, you will be destroyed by the supposed fans of the saga. For some reason.
So, I suppose it would be another 2D game. So, i don't care XD.
If metroid did the same, We never got Metroid Prime.
And by the way: I FUCKING HAAAAATE that "metroidvania" term some retard invented 10-15 years ago. Castlevania and 2D Metroid are NOT the fucking same thing. You can like one but hate the other series.