I'd love to get some of those unavailable sets as styles. They do have quite a few older sets that don't use the traditional styles at all, and it'd be nice to make outfits with them without having to use the actual set itself - that does limit the use of characters going for a certain look.
Hircine's Veneer
Shadow of the Red Mountain
Shroud of the Lich
Ebon Armory
Worm's Raiment
There are also the Briarheart (minor modification of Barbaric) and Maomer (sleveless modification of Ancient Elf) sets as well. We did get costumes to dress characters in full Reach Winder or Old Ashlander, but you can't mix and match with those.
Also the Asylum weapons and many of the Tier 5 racials are uncraftable styles.