Also leads to questions of development. How long until anything you ship is considered obsolete. On systems close by things aren't so bad if we are talking of a few years. But with tens of years, whole thing comes rather questionable. It is old tech when it arrives, and I can't even imagine the lead times.

On other hand new "new old stock", is quite interesting proposition. As items would be old stock, but still in brand new non-aged condition. So spare parts with limited life-span and lowish demand or complex manufacturing process might be the answer...