The Metroidvania game, and Castlevania’s spiritual successor, Bloodstained: Ritual of the Night came out in 2019 on multiple platforms, including the Nintendo Switch. Ever since then, it has been a success. In fact, according to publisher 505 Games in their fiscal year 2020/2021 Q3 results presentation, Bloodstained: Ritual of the Night sold more than 1,000,000 units worldwide and across all platforms.
But that is not all. They also said in the same fiscal year 2020/2021 Q3 results presentation that a “second version is in development”. Although the “second version” part is unusual wording, it is being assumed that they mean a sequel. To make matters even more strange, since the presentation came out, they have updated it to remove the mentioning of it completely. Whatever is happening, they apparently aren’t ready to say anything about it.