Of course it is. The opposite would mean DRM! But FSF-endorsed
distributions do not steer users towards nonfree software. Here is the whole
paragraph in the FSDG:
A free system distribution must not steer users towards obtaining any nonfree
information for practical use, or encourage them to do so. The system should
have no repositories for nonfree software and no specific recipes for
installation of particular nonfree programs. Nor should the distribution
refer to third-party repositories that are not committed to only including
free software; even if they only have free software today, that may not be
true tomorrow. Programs in the system should not suggest installing nonfree
plugins, documentation, and so on.
Debian does not qualify because it does not respect those guidelines.
However ADFENO affirms that "even Debian's "main" repository has some GNU