NOPE.
Although there were probably not any “non-binary” characters in Star Trek TOS, There were definitely some in Star Trek TNG. There was even an episode where the character played by Jonathan Frakes had an affair with an alien whose planet forbade HETEROSEXUAL relations.
Deep Space Nine had a character named “Dax” who was a male symbiote living in a very attractive female body. The captain even had a nickname for her: “Old Man”.
Star Trek Voyager had a chef/moral officer who pranced a bit, but it was never overt.
No way is anything today going to be a “FIRST” on Star Trek. It’s all been done.
I stopped paying attention to STD halfway thru season 1. If I need to see how badly its sucking lately, I just watch Doomcock’s reviews. They are 10X more entertaining than the show itself.
As for “first ever” non-binary and trans characters, the species Riker fell in love with in the TNG episode “The Outcast” (which itself was SJW propaganda but looks tame compared to the recent trash) was a “non-binary” society where they don’t have males or females, and Dax on DS9 was a “trans” character who had been a male 3 times and a female 5 times. The Trill symbiont lives for hundreds of years and joins itself to different hosts, male and female, over the years until the host dies of old age, and then it moves on to a younger host. When she met a young Dr. McCoy in one of the DS9 novels, and “came out” as having living a past life as a man, he was understandably uncomfortable with that fact and broke off the relationship immediately. (Dr. Crusher did the same in TNG when she learned her Trill boyfriend’s new host was female). Of course, that was back when Star Trek was sane.
It’s now a given whenever STD pats themselves on back for being the “first ever” Star Trek series to do something, its probably been done a dozen times before.
“Blu del Barrio”
She’d look cuter with long hair.
“Discovery” is just garbage, forget about the lib stuff, it’s garbage regardless. Klingon time crystals!!!!!!!!!!??? You could literally shit out better writing.