- The "removed" books had a weaker "hook" than usual: reformatting existing classes, expanding multiclass rules, etc, are not a strong enough draw to make expensive hardbacks out of. The sort of material produced for it seem to be more in line with the digital offering.
This is my general take on the matter. I live in a FLGS-free zone, so I pretty much order all my D&D books through Amazon.
I hadn't bothered to preorder any of these canceled books.