Apple wouldn't let customers "twist in the wind", it would sell them a solution.

An SSD is a wear item, and consequently a revenue stream. Imagine a replacement plan similar to the current battery replacement policy. Right now, you pay a fixed price, and they'll crack the case and swap out the battery.

Doing it for an SSD after some fixed amount of time would follow quite nicely, and give them the upsell opportunity. "Hey, while we're replacing the SSD, if you pay an extra $99, we'll swap in a bigger drive."

Apple is in the consumer electronics business, and part of their genius is in figuring out how to raise the annualized spend of their customers. The SSD is just another way to do that.