For Whonix software downloads? I don’t see any advantage of using keyservers even if they are functional. Users get documentation, software downloads, signatures from whonix.org. So can as well add keys there for completion. Doesn’t improve trust or availability by using keyservers for OpenPGP keys. Well, OpenPGP keys can still be additionally uploaded to keyservers but that’s just a bonus.
For the more general discussion besides Whonix software downloads, see: