Average Word Count for a D&D novel

[delericho]

Is the fact that WotC has very few "chunky" fantasy epics due to the fact nobody wants to write such a book for WotC, or that WotC has never asked, or something else? How likely is it that WotC might choose to do this type of project in the future?

I think this is highly unlikely. One common factor in all these BFEs is that they very significantly change the world by the time they're done. Wheel of Time will apparently end with the Last Battle. Song of Ice and Fire has utterly overturned the social order, and is only halfway through. Lord of the Rings featured the dawn of a new age. And so on.

Because WotC's novels don't stand alone, but tie in the RPGs, computer games, and whatever other media they can find to tie them to, they don't have the luxury of doing this. And when they do want to change the world (as with 4e FR), they tend to want to do so fairly rapidly - they can get three authors to write a trilogy changing the world and release it in a year, but they certainly can't wait the decade or more it takes for most BFEs to be published.

To do a BFE, they'd basically either have to invent a whole new world for it, or put one of their existing worlds out to pasture for the duration. I doubt either option is likely to be appealing.