I saw a question recently about the Blood Hunter class, which confused me because the D&D Beyond page for it is very visually distinct from pages for Homebrew, but everything I've seen indicates that D&D 5e has been extremely reticent to introduce whole new classes, instead opting to create more varied class archetypes (e.g. Divine Soul as a Sorcerous Origin). After a little investigation, it seems to be "special" for unspecified reasons. For example, it appears in the list of Classes as neither Official nor Homebrew, but is instead the sole occupant of the "Additional" category. Thus it definitely isn't "truly official", but somebody at D&D Beyond (an official rules source) considers it substantially distinct from homebrew.
So the essence of my question is, what separates Blood Hunter from being a normal homebrew class? I can think of a few possibilities, but the actual answer might be a combination, or something else entirely.
- Blood Hunter is actually official, but was published outside of sourcebooks so it gets weird treatment.
- Blood Hunter is a licensed 3rd party product, so is "approved" material but not considered official for purposes like being allowed in Adventurer's League play.
- Blood Hunter was developed by member(s) of the D&D 5e team, so is from an "official source" but only on a technicality.
- Blood Hunter is from a highly trusted source or has been recognized as high quality by the community, but is otherwise normal homebrew.