I'm not aware of any of the talented blender people doing anything like that, but Steve promised us more late war toys eventually, though probably not the Maus, but some of the more likely to have actually been produced goodies.
The Elefant is in CMRT Fire and Rubble and CMFI Gustav Line. I don't recall if it's anywhere else off the top of my head.
E series, Centurions, IS-3's, etc are what I'd like to see most after 40-41 in the desert.