I don't see how it's aimed at Americans as a whole.
East coast has been fine with getting up early for saturday kickoffs - 7:45AM / 10AM /12:30PM adjusted for time zones - already. Possibly west coast watchers, as they're a further 3 hours behind, would benefit from a move to a later kickoff.
So that would be an insane thing to cater to a subset of an already non-dominant market.
edit: I don't see it being a good move to draw in new viewers as saturday sports watching is fairly fucking dominated by college football already.