Just because the term was coined millenia later, doesn't mean that the origin, the etymology of the word you so dearly described ain't Greek. I have polydactylia, which idc when was it coined, but all I know is that I have a 2nd thumb on my right hand.
To my knowledge, poly isn't latin, it's ancient Greek for "multiple". So something along the lines of polyamore or polyamoria maybe? Irrelevant. Knowledge and Wisdom is what people can squeeze out of those lemons every person in history ever tried squeezing lemon juice from.
TLDR; Being able to love freely is the exact same concept as freedom of speech. Otherwise, trust me, I'm a boomer, and you a woke zoomer ;(