Lords of Shadow 2 & 3 are a must, and I honestly believe there will be a sidegame set in the LoS universe at one point. For everything else, such as a metroidvania or otherwise, given the past track record, a screenshot would've been leaked by now or a potential title would've been trademarked. Since we've seen nothing of the sort ("Complete Chronicles" was debunked I believe), and Cox keeps hinting at MercurySteam in control of the franchise right now, there's no reason to believe any of those "rumors."
One can argue the fact that Harmony of Despair exists is proof that Konami wants to continue making "traditional" CV games, but one could also take from it that it's just Konami milking the last drops of the classic games/characters so LoS can be in the spotlight.
However, a small piece of me still believes a metroidvania will eventually be released.. but the style/continuity it'll adopt is anyone's guess.