Assuming there's even a hint of truth to that rumor about Siri being dropped from the Prada Cruise campaign, I highly doubt Meisel would agree to shoot her for the S/S campaign. I also don't think Prada would ever cast their campaign this early (I've only heard of labels like Lacoste and Hugo Boss shooting before show season), so it doesn't really make any sense.
Not to mention that Siri would be pretty stupid to tell people who can't keep their mouth shot, had she actually booked the campaign.
So... I obviously don't know, but I definitely wouldn't get my hopes up. :/
.