Wow indeed! I bet that they don't let the car stay at 100% SOC for extended periods. Most likely the time it so that the car is 100% charged just before travelling. I wish the Model S had an option to charge to full with the expectation of leaving at a certain time so it will only reach the full charge a few minutes before unplugging.
With larger replacement packs becoming available before the original pack has deteriorated, it's worth knowing if any pack replacement is in exchange under Tesla policy or would a new pack be purchased outright and the client is left with a used pack to sell or part out.
There is a market for Tesla battery modules in the DIY community.
I think one of the US threads a while ago covered someone wanting to buy a new pack and was told that they had to surrender the old pack to do so. They got an allowance off the price of the new pack for it.
I suspect Tesla would want to limit the number of people taking apart the packs. The main source for used packs seemed to be salvage cars.
Of course policies may not be the same worldwide and may change over time?