[_ea1k]

It is a fair point that they didn't say it on day 1. Having said that, they've been talking about the potential for computer upgrades since at least 2017: https://www.theverge.com/2017/8/9/16119746/tesla-self-drivin...

I don't have time to dig it all up, but they were talking about the potential for computer upgrades as far back as 2016 as well: https://twitter.com/elonmusk/status/789008557341454336 (though not for pre-2016 vehicles).

I can see where people who don't follow the company closely wouldn't have been aware of this, though. And, obviously there have been plenty of false and misleading statements made in this area.