I'd guess the author of the post is on v12.3.3. Their experience with the automatic update and auto engaged FSD demo appears identical to my experience the past two weeks on v12.3.3.
While I think there is far to go in development terms, and I wouldn't recommend buying it either, my experiences on 12.3.3 are not identical to this at all.
Looks like the free trial cars are currently split across v12.3.2.1/12.3.3 depending on OS update.
Looks like the free trial cars are currently split across v12.3.2.1/12.3.3 depending on OS update.