This is a great history about the American intervention and subjugation of Filipinos. What caught my eye is your vehement reaction to the use of Filipinx/Pinxy. I'm sorry you felt dehumanized by the woman's use of Filipinx/Pinxy. I have not heard that term used as often as Latinx but I never realized it could offend a woman so much. I've only heard men complain that we shouldn't use gender-inclusive labels and that we're trying to impose our feminism on them. So I learned something new today.
I also thought I'd share that it's possible the woman who used the term with you believes as I do--it's a gender-inclusive way to identify people of Latinx or Filipinx heritage. To be honest, I see more WOMEN using Latinx/Filipinx because we see it as a feminist statement. But your point is clear--use the term that individual prefers and don't assume just because other friends of the same cultural/ethnic heritage like that term, this new person does, too.
You should feel free to share with anyone who uses that term that you strongly dislike that attempt to be gender neutral. I hope you'll let other people, especially those like me who are well-intentioned, know that you find gender neutral terms offensive. I continue to use Latinx in my writing because I know it's accepted by some people but if someone told me not to use it when talking with them, I would respect their position and switch to Latinos/as instead of Latinx.