I'll be locking this topic as your question has been answered thoroughly by the helpful users above. c:
A significant reason why it was removed was because it wouldn't fit in with the environment that we have now. The maps are composed in a way that makes more natural sense in the real wildlife-- so you won't find an arctic map a portal away from a tropical one. In the next patch, we're focusing on adding back in the variety of the old maps while still building off the current ones.