Well sexuality is much more complicated than the language we use to describe it. Bisexual is a term that comes from a time when gender was still very binary: two genders. We now know that gender isn’t that binary. Bisexual people CAN be attracted to only two genders but they can also be attracted to more (I doubt that ALL bisexuals will deny being attracted to non-binary people as well).
At the end of the day, it’s a personal issue anyway and everyone can define their sexuality however they want.
