It is a type of reasoning, just a bit twisted. By giving kids the ability to transition or seek medical interventions, you're also taking away the parents ability to control their kids, forced by the state which is a quick jump on the conclusions map to the other belief they've set up previously which is the state is brain washing kids to become trans through the state run education system.

So in their view, the liberals are forcing trans ideology on children while trying to remove parental rights.