A sequel to Bloodstained: Ritual of the Night is currently in development, according to publisher 505 Games.
In its fiscal year 2020 / 2021 Q3 results presentation, the publisher lists the following notes for the Metroidvania game:
Latest creation of Koji Igarashi, the former series producer of the Castelvania franchise. Worldwide publishing rights on PC and all console formats. High Metacritic score (average 81). €30.2 million life-to-date revenues—more than one million copies sold. Expected lifetime revenues of at least €30 million. Second version in development.
It should be noted that while “second version” is an unusual term