> 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 $4 }' | grep 'libexec/.*[a-z]d$'
While this exercise is illuminating, it is also depressing IMHO.
And the documentation, now it is mostly generated, the famous Apple books are now gone, at least the archive is still available.