Will this happen to foundational protocols like TCP? New developments (e.g. increasing the initial congestion window ~2010) keep taking place from time to time in TCP. I think technologies which have ongoing research will always have a pool of folks who understand them deeply. I'm not aware if that's true of NTP.
On a different note, your comment reminded me of what happens to the atomic generators as the Galactic Empire collapses in Asimov's Foundation series. As research and innovation die out, nobody understands how they work anymore, and their maintenance is taken over by hereditary guilds of "tech-men" who refuse to entertain the possibility of the great generators ever breaking down.