> One thing that scares me a little is whether there are younger developers, say, 25-40, who can and want to pick up the mantle of Windows internals gurus.

A similar "brain drain" has occurred in macOS (formerly known as OS-X) over the years, as evident in man page documentation for "newer" daemons shipped. An easy way to verify this is to run:

  ps -A | awk '{ print $4 }' | grep 'libexec/.*[a-z]d$'

And compare the man pages for the daemons running with the man page for `launchd`.

While this exercise is illuminating, it is also depressing IMHO.