Going bankrupt is not the only potential issue. There can also be situations, where a company makes several generations of a product, and abandons support for the old ones.
This is already a serious concern with eg. older gen chip fabrication. The machinery required for each generation was built when that gen was new, and when that machinery breaks down, it might not be economical to rebuild that capability.
Is this really a year old post? It was a good read regardless.
To comment on the topic, this is going to happen more and more, especially as proprietary stuff becomes more and more complex. With implants it’s obviously more serious, but this also applies to anything from cars to game consoles.
I’m no stranger to scrounging junkyards for car parts or ebay to replace components from an old console. However that cannot go on forever, as parts get more rare. This is somewhat remedied with eg. nintendo consoles, where some reproduction parts are available (cartridges, screens etc.). With more niche and increasingly complex products this option is often not available.
What happens, when the non smart microwave finally breaks and only smart ones are being sold? You could buy used, but what happens when that used inventory is used up?
Fortunately in case of microwaves, the simpler ones have the same internal parts as smart ones, and as such some supply is most likely going to be available.