The only thing I have found that is somewhat disappointing so far is that it’s not possible to play on the entire US map at one time. From the FAQ:
Will it be possible to play the whole American continent right from the start, or when unlocking all states?
The campaign spans the entirety of the USA, separated into large and detailed sections (e.g. East Coast, Southern States, etc). It will not be possible to play on one map that encompasses the complete landmass of the USA, though.
At this point I don’t find it to be a big deal as the sections feel quite large with plenty of play on each one. Maybe someone will mod it at some point or they will decide to make a DLC that encompasses the whole country.