I recently went on a formal AWS course. Advised to use Amazon's own Linux for machines, I pointed out that I would use Debian for preference because of licence and patent concerns and because I'd know what was in them and was told "Why on earth would anyone use Debian?" [The rest of my colleagues in the room collapsed in laughter at this point, since they know me].

Presumably Fedora containers would also be licensing and copyright appropriate: I'm not sure, given Red Hat policies on licensing and derivatives now whether I'd want to base containers on CentOS