Language and perception of sexuality changes, but "bi" comes from ancient Greek. It hasn't changed in definition in thousands of years, it means two,it will always mean two
Oh yeah, definitely, I think that if people couldn't find a way to make bisexuality work with an understanding that didn't incorporate some idea of duality, then they'd move on. And some have, hence all the confusion over the difference between pan and bi. But vertigogomez illustrated how people processed it, and it works. Shrug.
...although it is completely possible that by some quirk of language, the prefix bi will eventually not mean two. I mean, look at what's happening to "literally".
Languages are weird.