Nope, the Hungarian/Russian/Hussite War Wagons never made it into the final game as far as I know. They only appeared in a few preview screenshots.

Maybe there are still some of the textures/models for them somewhere in the files (I'm not that involved a modder, so I don't really know), but they're not in the EDU, and I don't think I've ever heard of a mod that put them ingame in any shape or form either.