Are there other WvW maps?
3 home worlds + 1 Eternal Battlegounds = 4 different maps.
“I was under the impression that these 4 ‘maps’ counted as 1 WvW map”
Wrong.
I hope in the future they add new areas within the overall WvW area (indeed containing 4 zones as promised). Perhaps in expansions. My only fear is that it will be a lot to keep track of far down the line and not enough people would actively engage all the zones when the server population would be lower for whatever reason.