It makes perfectly sense, but just like you I'm afraid something is off, and i think its not unlikely that the new title's development failed and was ultimately cancelled in favor of licensing out the IP for quick cash grabs without any expense on Konami's side. Im less optimistic and i see all of this as a signal thata new game is never coming out, rather than the opposite
Konami did expand one of their development studios last year. The original rumor was it was an in-house game that had notable third party companies developing it with them. Perhaps that changed into a fully in-house project with Konami wanting more direct control over development. Usually when they outsource games they get less involved, as the middling efforts from Silent Hill are a good example to this. The impressions I have from these collaborations is they believe that a new Castlevania game should be seen as a big deal. They never went this length to plug a Konami IP in the last half-decade unless it was within Bomberman. We've seen almost half a dozen collaborations within the last two years that I can recall just off the top of my head for Castlevania. There's even watches with a redesigned Belmont crest not seen in any of the games.
The most recent rumors are it may be part of a deal with Sony to get timed console exclusivity: these rumors surfaced just before people were leaking information of the Metal Gear Solid collections, so almost a year ago.