>>3
A court could see it differently since it is an additional writing.
Previously there never were never writings excluding classes of people.
Now there are.

It's similar, in a way, to prior restraint vs post-publishing action.
Previously there was just the GPL;
Now there is the GPL plus wrightings listing classes of people that are not welcome to develop the software.

Now you might say "that doesn't apply"; however the copyright of the derivatives (which Xonotic is) changes lies with the creators of those additions, edits, annotations. Along with the copyright to the original separable works bundled in the Xonotic distribution.
These writings excluding suspect classes speak to the mindset of the copyright holders.
They also wrote that they do /NOT/ want people like Kitsune to work on the code etc.
Darkplaces wrote the same.

To these works the "no pedophiles" additional writing could apply.
(note: Kitsune was a "furry" but they're calling him a "pedophile", if it matters)