I think you may be right as the dozen “bellwether counties” are not being reported. I wish I knew what the current sentiments are in Vigo County, IN and Hamilton County, OH. If they are currently leaning red, I would think in this atmosphere that they would be less likely to be reported.
I am sure both campaigns have internal polls on those bellwether counties.
The only way to figure out what is going on is to access to that data (hackers, hint, hint, hint :-) )