I've been trying to buy Super Fastpass from www.booktickets.disneylandparis.com but the whole of September is greyed out ("not eligible"). Does that mean those Fastpass tickets are not available in autumn/winter or that they'll probably become available later?
Super FASTPASS for September became available at a later date.
I was able to purchase it yesterday. I guess the initial inavailability (in June) was due to the different price policy for September - weekdays are cheaper beginning with the second week of September so maybe the powers that be had to look into the demand first in order to know what to offer (at what prices).