I'd love for them to come back as well.

They will probably add them to the mog station at some point. The real question is when? They've been really silent about this, and lots of people would gladly buy the lightning and snow costumes (it's not like they wouldn't profit from doing this).

There's really no reason not to put them up there, except for superficial reasons such as "ugh, everyone would be running around with lightning's hair, i hate it" or "i hate the mog station, they shouldn't put anything in there ever"