This is because of how IS made the Cutscene only Asset IDs function (which is what everyone who doesn't change models on reclassing has).
Basically, by being a cutscene only Asset ID, the game is unable to alter their body model's appearance in any way at all, which is why the odd behavior happens.
Same with the Accessory shop, it loads every Asset IDs into memory in a different way than the game normally does, so that it can delete and load a new character by simply modifying the AID that was loaded, but because the cutscene only AIDs cannot be manipulated, the game is unable to unload them.