You see I think a lot of NT people do do most of that stuff. Ok it's not suppressing their autism per se. But putting on a brave face; pretending to be less shy than one is, or more confident, or really interested in football to get a guy to like you, or that you are not into Abba because to admit you like it would be social death. Panicking that you don't have the "right" haircut, or bag, or shoes (especially in teen years). Worrying that people won't like you. We absolutely rehearse what we are going to say etc. Maybe some very robust non- introspective extraverted NT people genuinely don't, but most everyone I know certainly does. In fact my DS has always had a certain freedom in this respect as his particular autism manifestation frees him from giving a damn about what other people might think of him.
There is some research that suggests that the main area of difference between autistic and NT people is sensory masking. Here:
“Masking Is Life”: Experiences of Masking in Autistic and Nonautistic Adults - PMC https://share.google/su2kttZVGhbTfmTNw
Why do I think messaging around masking is pernicious? Because I think it gives autistic people the incorrect impression that NT people are sorted, don't mask, don't introspect, don't worry about how they are perceived socially, don't lie awake at night wondering if they have offended X or if Y hates them. When in reality most adults are fucked up one way or another to a greater or lesser degree by their experiences, upbringing, traumas, etc and just trying to make their way through the world as best we can.
I suppose I mean that I don't have a direct insight into autistic masking but I do know for sure that I have many shields I adopt in different circumstances which I also find tiring, and so do most other introverted people I know. I adapt this to reduce draining my battery too much - for example, if I have to go to party, I will spend 30 mins circulating and chatting "showing my face", then I retreat as far away from the loudspeaker and just talk to someone I already know, ideally in a quieter room away from the hubub. If I am in a pub with loud music I ask them to turn it down a bit or leave. If I am talking professionally I am substantially more confident and assertive than interacting with someone outside my professional sphere.
Fwiw, my kid's severe burnout was triggered by expectations of NT learning trajectory in the national curriculum, and this causing huge cognitive dissonance and incremental trauma as a bright autistic person who couldn't flourish in a NT education curriculum.