Board Thread:General Discussion/@comment-31412778-20170508154958/@comment-1038387-20170508155414

Wikis with different licenses are mainly grandfathered in - they had the license when Wikia took them over and it was one of the conditions of the sale. But there won't be more than a handful, and several have changed to standard since.

Nothing you say on the main page or anywhere else would override the sitewide license on written text.

Your best bet for another license is to ask via Special:Contact/general, but it's a slim chance.