It's also possible that the retina display is a horribly expensive part, and, to keep the (rumored) price increase to a "minimum", they had to reduce the memory. I'm not saying that this is going to happen, but it is plausible.I bet Apple spread this rumor to lower expectations and to later have an even more positive feedback to the announcement of the 64GB and 128GB models. Why wouldn't they release such models in times of product diversification? Just to force some people to use iCloud, are you serious?
Edit: it's also possible that Apple is sending out "confidential" misinformation to see who is spreading the rumors.