Yep, that's correct.
Ironically I myself might fall under the group she allegedly thinks exists. But a critical part she (probably intentionally) misses, is that I didn't "turn" trans because of online communities. People don't "turn" trans, but explore their identities and figure it out, it's a long process. The community merely helped me in figuring out what all my things together were. And that's why the group she invented on the spot, doesn't exist.
Before exposure to more queer stuff, I already knew I didn't like having body hair, and long for having a womb, and so on... but I didn't have a "name" for those together. I only knew I felt meh in my body and didn't really feel 'at home'. When I finally started to figure it out, it gradually 'clicked' and helped me!
To take a parallel. Just because formal English doesn't distinguish "thou" and "you" anymore*, it doesn't mean that English speakers don't understand the concept of multiple people.
* Yeah, I know of 'ye, you lot, tha, yinz, (all) y'all', etc., shuttup shuttup ඞ. Bear with me for a second.
Or like how spoken Hungarian, Chinese, and Estonian do not distinguish gendered pronouns, instead having a neutral one. That doesn't mean those people don't know what a man, woman, or enby is.
And to hit the nail in the coffin even more. If a language like Russian distinguishes 'blue' and 'breen' (blue-green) as standalone colours in their own right, does that mean they can distinguish them and anglophones can't?
No. People are familiar with them. It's just that not all know the word for the concept. Knowing the concept-word helps in understanding, though, and so it's time for a nice xkcd (explanation included for the lazy).
I don't care if I've ranted too much, get a nice cookie here and enjoy. 🍪