I think it's a good idea to post this to opengameart
While there are artists with accounts at opengamearts present at freegamedev, still site's goal is a little different.
However, yes, automatic adding of the license information looks much better than adding it manually. E.g. as far as I remember OpenGameArt user agreeement additionally requires inclusion of the link back to the site (most useful would be a direct link to the content, which will actually appear only
after the art has been submitted).