AFAIK, the distribution isn't "bootstrapped" (rebuilt entirely using itself
as the build host),
I kind of determined this empirically. It doesn't build from itself, therefore,
Red Hat is not shipping binaries that is built from the actually shipping copy of
all the srpms. This is bad news for any group that needs the ability to rebuild a
distribution to prove they have the complete set of source and can re-create it
if they ever needed to; or prove there are no 3rd party add-ons/hacks. (There are
govt institutions that require this.)