From wikipedia: https://en.wikipedia.org/wiki/Latinx
Origins
The first records of the term Latinx appear in the 21st century,[22] but there is no certainty as to its first occurrence.[23] According to Google Trends, it was first seen online in 2004,[11][24][25] and first appeared in academic literature around 2013 "in a Puerto Rican psychological periodical to challenge the gender binaries encoded in the Spanish language."[23][26] Contrarily, it has been claimed that usage of the term "started in online chat rooms and listservs in the 1990s" and that its first appearance in academic literature was in the Fall 2004 volume of the journal Feministas Unidas.[27][28] In the U.S. it was first used in activist and LGBT circles as a way to expand on earlier attempts at gender-inclusive forms of the grammatically masculine Latino, such as Latino/a and Latin@.[24] Between 2004 and 2014, Latinx did not attain broad usage or attention.[11]
So apparently, it was academic Latinos or Latinas that first coined the term. But in the US, it seems that it was first done in activist and LGBT circles. I'm inclined to say that this latter group is white leftists. But obviously it was coined before that by Latinos (let it be known that this is a term that includes Latinas if both genders are involved).
So I agree with you GWN partially. I'm sure it was not white conservatives that came up with this term. Can we agree with that?
mspart