It's only been about 10 months. Give it time. After how badly Mirror of Fate and LoS2 did, I'm not surprised they're staying a bit quiet on it. Castlevania was doing yearly releases for a really long time, and as a result they were mostly samey (despite being actually good and polished games). And then there was the whole era of badly received games.
-Judgment, the fighting game with good intentions but terrible execution.
-Harmony of Despair, the online multiplayer Castlevania that was essentially Frankenstein's creature, lazily made from pieces of other games.
-Lords of Shadow, the actually good game that was unfortunately too much of other games and not enough Castlevania.
-Mirror of Fate, the extremely short 2D Castlevania that still wasn't very Castlevania.
-And LoS2, the extremely underwhelming ending to the LoS trilogy and was ultimately the worst of the three games, and considered by many to be one of, if not the worst game in the series.
So basically, after a killer streak like that, I think they're probably playing it safe and giving the series a bit of time to cool off for now.
If you guys want some Metroidvania goodness, though, go have a look at Chasm. It captures the Metroidvania feel far more than any other game that has attempted thus far.