I would assume that those who have already obtained the badge would keep it, while those who haven't managed to get it yet will have to obtain the new spells added to get the badge.
But who knows? Maybe everyone loses the badge, and have to hunt for the new spells in order to get it back.
Just like previous updates that have included new school spells, while they do not impact players who have already earned the badge, players going forward will need to ensure they have all the spells.
Once a badge is earned, it is not removed. (unless, it's a bug, which when we fix will re-apply itself...)
If you want the prize, you have to build the ladder rung by rung. There are no shortcuts.
