I always thought Apple should have offered free battery replacements, ideally ones that had been re-engineered to better maintain voltage, so I think Chevy's approach is good here given the predicament.
Having to accept a very small risk of fire or lose range temporarily is really unfortunate, but all 2017-2019 owners are getting a 6kWh (20ish mile) upgrade in addition to everyone getting a brand new battery with a fresh battery warranty. Options for buy back or partial refund would be good to present as options but idk how many people would take it in this car market and/or with the option to get a brand new battery.
If an owner wants a buyback, the automaker buys it back. If the owner wants to keep the vehicle with whatever changes need to be made to make the vehicle safe, they keep the car and a check is cut to make them whole for the diminished value of the vehicle.
That is purely hypothetical, however -- as far as I know, this kind of stunt has only become a thing since Tesla started doing it. Chevy wants to reduce the capacity of my wife's Bolt by 20%, but they are asking for her permission to do that, not just sending an OTA update to do it against her wishes.
When I look at what car to buy, I am not going to care so much about regulations or legal ramifications, I'm going to look primarily at how likely it is that I will have to resort to those remedies in the future because the manufacturer likes to modify already-sold vehicles after the fact without even asking.
Stunts like this are why we are looking at a Mach-E to replace my wife's Bolt, not a Model Y.