> The previous owner shouldn't have sold it as a 90 or at least disclosed that, "It's a 60 but Tesla swapped out the batter with a 90 and left it configured as a 90"
I'm not as sure about this take. Imagine if this were something not connected to The Cloud; the seller sells the car they have, its not their responsibility, nor should it be, nor has it ever been, to know that this is a component that's Cloud Connected and Tesla can just take it away with no notice. No other car operates like that; even the new BMW shit isn't like that, its pretty clear "this is a subscription which is bound to your account, not the car".
Very few consumer physical goods operate like that. Here's a correlate: Intel bins chips. Imagine you buy a computer, you get an i5, years later its upgraded to an i7, years later Intel rolls around a software update and says "your desktop only shipped with an i5, we're disabling two of the cores". That's theoretically totally possible with Intel & partners control over microcode & chipset updates; but it would be wild to happen.
Now, put yourself in the shoes of someone selling that desktop: you sell the computer you have, it has an i7, "two years ago the chip was upgraded", that's it. Let's say the price difference between these two chips is, like, 20% of the total cost of the machine. Would you, the seller, accept 20% less; in other words, selling the laptop Intel may or may not create for the buyer, in the unknowable future? Would you, the buyer, be willing to pay 20% more, even knowing (or, more likely, not knowing) that Intel could nerf the performance at any time?