Here is a link to the azbwiki Exemption Doctrine Policy which is required by the Wikimedia licensing policy for any Wikimedia project that hosts non-free content.
I think we would want to see the EDP prior to enabling. So, according to WMF board licensing policy, each project having local uploads needs to have an exemption doctrine policy, which explains when can be non-free files uploaded.
Thanks @Aklapper and @4nn1l2. You now need to schedule your patch for deployment. You can do that using https://wikitech.wikimedia.org/wiki/Deployments (all windows titled "European Mid-Day SWAT", "Morning SWAT" or "Evening SWAT" are applicable). During the window, you should be present in #wikimedia-operations IRC channel. A member of the SWAT team will then guide you through the deployment.