I love costumes! I agree that these outfits should be made available for the “Wear Costume” tradition, they are great.
Also, it really irks me when things does not mesh ingame. Instead of just letting yourself be immersed in the game and seeing it like one great experience you start thinking about the the little blocks that it’s is made off. That just really pulls me out off the game, when it doesn’t feel like one world your sim is living in, the very same outfit you had last month at a spooky party is now off limits.
Things are forgotten sometimes, just hope they will add them sometime soon in a patch. The costumes are great and it is one off my favorite stuff packs.