It of course would be updated and edited regularly, though perhaps not the instance a map went live. But once a map is up for live play, it would be taken off the 'Developmental Atlas'. And any new ideas that are taking shape would be added.
Two days sounds about right for a map to wait for last minute objections. I'd personally give two and a half or three weeks for fixing errors, just in case someone is going on vacation at the wrong time (although I'd hope most errors would be fixed within a week). And while I can't say that we need a developmental atlas, it does sound like it'd be handy.