GW wont let go of their properties. Fantasy is a massive cash winner for them second to 40K sure but still massive. They cant sell that and even selling Warmaster would have to include most of the IP at the 10mm scale. I am not sure that Pendraken would even be interested!
That said, a fantasy game based on the Commander rules engine would be great (and, no, the irony of that statement is not lost on me).