“Standing on those steps and seeing that this is such a heroic moment, this is a culmination for these [draft picks], we set out on, ‘Could we create a theater? Could we build a theater here?’ ” said Peter O’Reilly, the NFL’s senior vice president of events. “We know it’s going to be complicated. We know it’s going to be audacious. But this is what we have to do, and the Parkway itself was natural. It’s a home to so many iconic events over the years.”