as a gen z, there's a considerable fraction of mostly girls who identify as bi or nb just bc it's "trendy". tbh it's a problem and lowkey trivializes people who actually are those. i think this is what happens when you emphasize a "lgbt community", young people seeking community will join for no other reason.
Vast majority of new cases of "B" are likely to be cultural. i.e. White women in HS/Uni. Declared, but never expressed.