The map seems somewhat 'boxy' to me.
I don't think they have tried to make maps for aby of the specific worlds because nexus is kinda its own place, and if they have a diablo map, they might need to have a starcraft one, and the a warcraft one and etc.
They have been thinking about making some Wsg/AB maps off the Wow battlegrounds. I honestly would love a wsg/ab without any minions exactly like in wow.