This is old news, but as I understand it, there were several reasons that the drone performance was not done live:
1. The stadium is actually in class-B airspace
2. The NRG stadium was restricted airspace during the Super Bowl
3. The weather.
Part107 allows for the operator to fly in Class-B (with permission from the controlling ATC), but the FAA wasn't going to allow them to fly above a stadium which had tens of thousands of people in it, so they had to film that sequence prior to the actual event.
Some people have made a big deal out of the fact that it wasn't shot live and have even suggested that it was CGI. That's unfortunate because that detract from how spectacular this event was. It was shot live, just not at the time of the Super Bowl.
I forgot to mention that the reason Lady Gaga was pre-recorded was because of the weather. I believe it was raining during the game. That was probably one of the best halftime shows ever, that didn't get the notoriety of other halftime shows because it was during arguably the greatest Super Bowl in history.