Earlier quoted context omitted.
Those things are immortal right until they suddenly die without a warning. In 100 years there will probably be somebody maintaining Linux for sentimental reasons. But it probably won't be in practical use.
I sincerely think Linux is “too big to fail” at this point. Will it morph and evolve into a charmander? Probably, but the evolution will be fluid.
It's hard to imagine this happening to Linux in particular because it's ridiculously flexible. But things always change.