Sure, I get it. I've used the term many times.
The left is great for devising terms for things that are not real and then framing the debate so that we are forced to use their terms or else constantly correct their terminology. Doing that drags down debate, which is exactly what the left wants.
We could call him any number of things: delustional guy, cross-dresser, fraudulant participant in female sports, digital rapist in this specific case, and locker room peeper, brownie hound, bathroom voyear, masher, etc. for dudes that invade female spaces.
But we say "transgender" so we all know what specific delusion/fraud we are talking about and so the wokesters cannot say "I don't know who you mean."
From now on, I'll put the word transgender in quotes as above to indicate that it is not real.