Even though the featured playlists' strawberries are converted to gems, it appears as if strawberry-carrying cats are still present in Furbottom's Featured playlist. When killed, their "loot" is still a strawberry as well, although when picked up, will count towards your gem count for completing the level.
Examples from the Strawberry Lake level in the Buckle Ur Pants playlist:
No negative effects from this bug as far as I can tell, but figured you guys should know.