There is a separate map (actually several) with all the Sprint Towers in the sponsor' section (that you can see). The main map only shows sites that have been accepted or marked in progress. Sites marked in progress come from member reporting that work is going on. All 38 thousand sites will be receiving NV upgrades. There are around 100 won't be receiving LTE upgrades, there is a thread in the sponsor's section that discusses them, but they should be receiving all the other upgrades.
As for the sites not completed around you, work may have already started. If not they should probably start soon since Michigan was one of the earlier markets.
Sensorly may help you determine what coverage looks like in your area but since you are rural it may only give a partial idea.