The batteries have been already manufactured and you physically have them in your possession as they are there in your car; they just chose to artificially cripple their capacity in software.
If not, then it is no different at all from someone dying in a Ford Focus that was only front wheel drive where all-wheel drive would have saved their lives.
If the FWD version also came with all the parts that the AWD one has, but they were simply disabled in software and only acted as dead weight, people would be just as furious (and no doubt someone would find a way to reenable it.)
Tesla restricts your battery usage for battery life purposes.
This allows them to sell you a vehicle that has a charge matching what they claim while also having a battery life matching what they want it to be.
SSDs work similarly. You don't sell 1 TB of SSD storage you sell slightly more than 1 TB worth. Then you wear level between cells to ensure the whole thing lasts a lot longer. (Batteries are nice because losing a cell isn't losing data but the fundamental strategy isn't anti-consumer)
Imagine cars came with governors for instance that could restrict speeds and acceleration to limit wear and tear on a vehicle and provide the consumer with a lower cost upfront thanks to less warranty work needed. Similar concept.