IMHO we are free to think what we like. We should be free to say most things too, but some things we need to be careful not to say, or careful about how and where and to whom we say them to.
So if you happen to think e.g. the terrible thought that we can abbreviate as TWAM, but you'd never actually say that aloud because you're careful about who you express it to (and you're not in Scotland so Alexa can't dob you in if you mutter it in your sleep) you're fine, right?
What if you think TWAM and you turn around and leave when you see a TW in the ladies', who consequently takes the huff and reports it as a Hate Incident? Do you think that's too ridiculous to really happen or something? If you do, you haven't been following this debate for very long. Nothing is ever too ridiculous to happen.
What if you think TWAM and you turn a TW down for sex because you're not into men, and get reported for it and a Hate Incident recorded against your name for the pain? That actually HAS happened.
Could it be a Hate Incident to not put your pronouns on your email? It could! A Hate Incident can be whatever you want it to be! All it takes is for someone to identify the incident as a Hate Incident and tell the cops about it.
If your wrongthink has any kind of impact whatsoever on your behaviour, a sufficiently paranoid or vindictive person can sniff that out and report you for it.