I'm familiar with the neighborhoods -- you're fortunate to live there (I'm jealous!)
I will debate whether or not they have been reviewed -- I suspect they have been (would you really notice someone wandering down the street snapping pictures, maybe talking into a recorder -- or even writing on a clipboard?)
Deciding what qualifies for registry nomination is complicated, confusing, and subjective (though you wish that last wasn't true). Not too long ago I surveyed 264 structures in Las Vegas (the city occasionally fails to demolish buildings -- but not often. sigh.) Anyway, out of all of those, in the end, there were 11 potential nominations -- and one is already on the state registry. One of those is a neighborhood of homes built in 1951. I doubt that they will actually be nominated, when they are old enough.
I don't necessarily disagree with what you're saying; just pointing out that there is a process.
If you're interested, pop over here:
http://www.cr.nps.gov/NR/listing.htmand scroll down to "What are the criteria for listing?"
That's pretty much what you start working with.
You may notice that it indicates that a property has to be at least 50 years old (or exceptionally important) for listing. The key word there is "listing." State SHPO's (state historic preservation office; part of the state government) rules for reviewing a property may differ - but even if the structures need to be reviewed, they can't be listed on the National Register unless they meet the criteria.
I'm not familiar with MS law, but I suspect that this is more along the lines of other development projects -- you have to make sure nothing important (nice subjective word, hmm?) is there. Sometimes it's an archaeological survey, and sometimes an historical one. Nine times out of ten, it amounts to nothing and the development continues apace.