I really loved the old GW1 maps. You got a real sense of the Zombies encroaching on the neighborhoods in those old Turf Takeover maps because they literally started in places like Zomboss's mountain fortress or in old graveyards and the assault would start you in undeveloped wilderness areas and the map would gradually become more settled with houses and shops and urban development coming in organically as you headed towards your goal.
GW2 lost some of that with a few of their maps since they deliberately went for more exotic themes but a few of them, like Frontline Flats, Zomburbia, and Moon Base Z, had a bit of the same flavor in that you could get a sense of starting in one place and progressing over a distance into new areas but the BfN maps just seem like you're moving through one big area instead of from one area to a new one so they give a different feel.
I remember that the GW1 maps were never designed with some of the newer GW2 characters in mind, specifically some of the variant Mechs were huge in size, but they did give us the Aqua Center which PvZ vets would recognize as the old Garden Center map from GW1 now firmly under Zombie control.
I would actually pay a reasonable price for DLC if they were to update some of the older maps to account for the newer classes and roll them into BfN.