In article .com,
wrote:

You better hope that Garmin does a lifetime buy on critical end-of-
life components to be able to support it for decades to come. All big
avionics companies do this as a matter of course since their product
life-cycles tend to outlast commercial electronics by many
generations. Processors and memory ICs tend to be the parts that have
the shortest life-cycles and need to be stockpiled.

Not just stockpiled, but jealously hoarded and rationed.

A bunch of years ago I was doing a repair job on a piece of lab equipment
which had an embedded process control computer made by HP. One of the
eproms had been damaged. I tried to order a new eprom from HP but was told
they were no longer available. It took a while, but when I finally got to
the right person and explained to them that I had a piece of dead gear and
needed this part to fix it, the answer suddenly became, "Oh, of course
we've still got a few stashed away and can sell you one".