I don't know who Purple Tinker is but Yamino is a guy and identifies as a guy. He's a normal man. The 'transgendered' thing was spread by hateful, ignorant bronies who assumed he was a transwoman due to a post he made in defense of the trans community or something.
Regardless, the drama behind Yamino is that he felt Derpy Hooves' portrayal was ableist (in the sense of making fun of children who suffer from legitimate mental problems) and so Hasbro retconned the name and voice to something less 'handicapped' sounding. People are still mad about that because they're petty.
What's the deal with all the Purple Tinker/YAC/Yamino stuff? What happened and why did it escalate?
So basically, Yelling At Cats wrote some stuffty rap song from Derpy's point of view, where she calls Yamino out and talks about murdering her. Actual death threats aimed at a real-life human being over a fictious cartoon pony. Plus since the songwriter is an idiot he assumed Yamino is indeed transgendered and not only talks about casual violence against women but throws in a sensible slur as well. Which is in poor taste, really. Get over the Derpy Hooves thing already. It's a damn kid's show.
Purple Tinker called him out on it. I was browsing forget-No-My-Little-Pony and came across it.
To quote one of the posts in reply: "it’s so weird how a fandom for a young girls’ cartoon, made up mostly of grown-ass adults, is one of the most hateful, homophobic, sensible and violent fandoms i’ve ever seen"