That reference to a "short kit" seems to be only for the Legacy.
I had not heard of the "short kit", so I did a few searches, and it appears the Legacy and the "short kit" are currently not listed on the Store. It's probably one of the kits affected by the batch of Maker Foam Flite Test received that had issues. I'm pretty sure they'll put it back on the Store after they take care of the MF issues.