One more thing, Gaga, the cast of Hamilton, and anyone else is probably under intense peer pressure to
make a statement. Not doing so when given the opportunity would be akin to being a sellout to the (resistance) cause. Her record sales would plummet, the Hamilton production would have to close up shop.
So they WILL do something and Hamilton can triple their ticket prices.
The NFL might get a boost in ratings, at least initially because of the "can't look away from the trainwreck" effect, but the blowback of Colin Kaepernick's stunt has already cost them ratings and serious money. The last thing the NFL wants to have happen is for them to be viewed as taking sides politically. The cast of Hamilton will only be the three actresses who originated the roles (but who are no longer in the show) of Eliza, Angelica and Peggy Schuyler, and will be singing America the Beautiful at the pregame ceremony. The halftime is solo Gaga (with dancers, of course).
Some of her fans have Twitted that they'll be mad if she doesn't make a political statement, but many more people have said they'll simply flip the channel from the game if she does. One Twitted "@NFL @CBSSPORTS @Kia @Budweiser @ladygaga one mention of political comments @SuperBowl and the tv goes off and we will not support your brands."
Personally, I don't think she'll go very political, if at all. I think she'll make it about the music and about the performance.
Of course, the NFL will crap their pants if she looks into the camera, holds up a picture of a Pepsi can, and rips it in half.