We just had our second Fantasy cruise this past March(the first being the MV last year),and I do remember a memory box listed for both cruises, so I was surprised to see your post. I went to the site and sure enough,the non-food items are totally different from what was being offered just in March! Some individual items were still there,like the backpack, but were in new configurations/gift sets.
I'm pretty sure the memory box had Goofy on it...I can't imagine they would be totally sold out of every one of those. I would try contacting someone to see if they could go on a kinda treasure hunt to scrounge one up for you. I think one or more phone calls are worth a try. I've personally found that if one CM doesn't know the answer or comes across with an "I'm not sure/I don't know", you can guarantee, someone somewhere has the answer.
Persistence and patience can pay off.