For all the talk about expressing yourself and being the real you and all this happy-crappy bullshit, it's very psychologically manipulative.
The things that make me think of a cult are these:
1. Identify as an NB and change your pronouns and people will come out of the woodwork to tell you how amazing you are.
2. If you express any doubt or skepticism, you are a heretic and true believers must avoid you. If your mom doesn't want you to get top surgery at 15, she's a suppressive person. If you cut your tits off and then later realize it was a mistake, you're an apostate. People who leave generally leave quietly so they're not the focus of two minutes hate.
3. Re-defining words such as "woman," "vagina," "clitoris," and so forth.
4. The time-suck and money-suck elements. Being a troon is a full-time job for Jazz. Or people with no visible source of income obviously spending hundreds a month on clothes, makeup, hormones, wigs, tampons, and so forth.
5. Thinking that everyone outside the cult is an enemy, or grouping the world into the benighted cis versus everyone else. 41percenting and talking about the troon murder rate are part of this.
6. Use of thought-terminating cliches. "TRANS WOMEN ARE WOMEN!"
7. Letting troonery be the center of your identity and self-esteem, and letting the group be the cure for all your ailments, both physical and psychological. Keybored used the words "malignant narcissism," and while I don't think every troon meets the DSM definition for narcissism, there's a lot of parasitic behavior there on all sides.
This link has a pretty good list, but it's not the only source I drew on for the above list:
Warning signs to look concerning cults and unsafe groups
culteducation.com
Obviously, there are things that are not cult-like. There's no centralized leadership, there are no mandatory meetings or tithes, and there's no explicit theology (but I have extensive thoughts about the implicit theology).
Thanks for coming to my TED talk.