Free upgrades, as in what - if, in the future, you need additional hardware for later features?
Highly unlikely, I think... they already drew that line in the sand when they started calling 2017-2019 cars back to give them AP3 computers. That was a huge expense they had to swallow, and the only time they've ever done it. Extremely doubt they'd do it again. They're more likely to just not offer those features (though more likely: that performance/smoothness) on AP3 vehicles.
The camera retrofit is a relatively small number of cars, I think (it was only Model S/X, which were much, much lower volume than Model 3s), so that's not as bad as ever, ever needing to do a retrofit on the hundreds of thousands (over a million now, probably?) of cars that have AP3 hardware.