I was hoping more groups did stuff like this. The free sites doing it could handle some copyright issues if their EULA had a built-in license for distribution. In my previous analysis, (IIRC) I found that Wikipedia articles were under a copyleft license with attribution requirements. Does how Wikipedia Enterprise delivers this bypass that where neither use nor derivatives have those requirements? Or are they ignoring…
However keep in mind that different wikimedia content is under different licenses (e.g. wikidata is public domain). Additionally in the united states, if you take just the factual content (removed from any creative context) the facts are not copyrightable so the license does not apply.