It's not just staying true to the first Bluzone, it's staying true to what's already embedded and woven into the map. Anyways, some people talking about how the infection started doesn't affect the role-play a whole lot - so it's not messing anything up.
How does making the location anonymous detract from role-playing? Sure people talk about how they got there, and that place is the Bluzone. Not Central America, not some country-side in England, not the mid-west - The Bluzone. And thats's fine enough.