With any Wagn upgrade, we may make changes to the Cards on New Wagns that come with a new Wagn, or add new default cards. With the upgrade we include a script which "migrates" existing cards on your Wagn with the new, updated content. However, we don't migrate cards that have been edited by anyone other than WagnBot, because we don't want to override custom changes you have made. You can see the list of cards that were changed on any release's +migrations card, and look at the changes we made and merge them in by hand.