What
Enkeria said makes totally sense. IGA said, more than once, that the biggest mistake he ever made and what he most regrets was mistakenly publishing Castlevania timeline, because not only they revealed they had cut several games from the canon (later on, notably both Castlevania 64 games, Legends and Circle of the Moon) but because that restricted their games to a certain time frame.
At the time, some people even accused IGA of being sexist, due to removing Castlevania Legends (the only Castlevania game with a female lead) from the timeline.
Order of Ecclesia was crafted for the specific reason to shrug that off and IGA himself said that the main reason that game has a female lead was to please the fans, since it was an old request to them. And he specifically crafted Order of Ecclesia's plot to make Shanoa really powerful too.
To those curious, THIS is Castlevania's official timeline:
Castlevania: Lament of Innocence — 1094 A.D
Castlevania III: Dracula's Curse — 1476 A.D
Castlevania: Curse of Darkness — 1479 A.D
Castlevania: The Adventure — 1576 A.D
Castlevania II: Belmont's Revenge — 1591 A.D
Castlevania— 1691 A.D
Castlevania II: Simon's Quest — 1698 A.D
Castlevania: Harmony of Dissonance — 1748 A.D
Castlevania: Rondo of Blood — 1792 A.D
Castlevania: Symphony of the Night — 1797 A.D
Akumajō Dracula X: Tsuioku no Yasōkyoku — 1798 A.D (Not a game. internet and CD radio Drama. It is considered canon)
Castlevania: Order of Ecclesia — 18XX A.D (specific date is unknown)
Bram Stoker Dracula — 1897 A.D (Not a game. Quincy Morris, from Bram Stoker's novel, is considered a distant descendant from a branch of the Belmont's family)
Castlevania: Bloodlines — 1917 A.D
Castlevania: Portrait of Ruin — 1944 A.D
Demon Castle War — 1999 A.D (Not a game. A event, described on Aria of Sorrow, that killed Dracula for good)
Castlevania: Aria of Sorrow — 2035 A.D
Castlevania: Dawn of Sorrow — 2036 A.D
Akumajō Dracula: Kabuchi no Tsuisoukyoku — 2037 A.D (Not a game. It's a novel and it is considered canon)
Everything else is considered alternate timelines and universes.
So, considering all that, it's no surprise that, if they hope to turn Bloodstained into a franchise, creating a spin-off right away can free their ties to a restrict and convoluted timeline, like what ended up happening with the Castlevania franchise.
The mini-gmae being a spinoff can have several meanings. It can be something like Final Fantasy series, where several games shares the same elements, but happens at different worlds. It can be different timelines and multiverses and whatever you want, you can combine them to create a new game focusing on paralel universes and timelines (like Castlevania Judgment). The possibilities became endless.
I'm sure, considering how many times IGA mentioned "his biggest mistake", that he is actually working around to completely avoid what we are seeing above haha.