I'm starting to hold to my original belief that Sprint is now even hiding some completed sites even from your source. Either that, or they are being really picky on what to accept and their are a ton of towers that will go online right at the end of the year so they meet their 12,000 tower target.
Or the 3rd scenario: Your source is going to dump a bunch on you all at one time just to make your work 100x harder to push out a map update the same day he sends the completed sites to you,
Personally, I think they are being picky on what they accept.