So I did take photos when I got home yesterday. As you can see, they just put one on top of them and this one did not say priority anywhere on the actual sticker. (Also surprising as I would have thought this is automatic by the computer.) And it was presumably done in SKG, as it has the information of both flights on there. And they kept the original transfer tag. So not like they ripped off the tags to replace them but just couldn't find a priority tag.

Edit: Also, the new stickers had different numbers that did not match my stubs.