Did they ever actually say The Old World is going to be a normal 28mm game? Could it turn out to be something like Epic was for 40k?
The smaller scale would both make it need less sculpting work as it would be hard for Forgeworld to make as many new kits as you would need for all those old armies and I can't see them using too many old models again as they would want you to buy new stuff.
It would also make it way less expensive to get together full armies, I wasn't in the hobby when Fantasy was still around but as far as I know a reason it died was that it had a pretty high hurdle of entry in cost and number of models which a smaller scale would help to alleviate.
Maybe not as small as Epic was but still smaller than 28mm?