I always thought that admins of Linux installs other than Fedora and Red Hat installs rarely bothered with selinux and that it is definitely not enabled on an initial install.
I thought selinux was available as a package on non-RH distros, but install it and enabling was very painful unless you are an selinux expert, so almost no one on those distros does.
I've been a fedora user and Red hat user since 2010, and worked at Red hat for a few years, though not on RHEL.
I think they did mean selinux. You are absolutely right that nowadays it just works for the most part. The big exception is for people deploying applications that don't have selinux config shipped by Red hat. Those people have to configure things properly, and rarely do people bother. If you do things like change the default ports for services, that can also get you in selinux trouble.