How? I know the event is a little more exclusive than the press conference is, but it would seem more logical to me that they'd show it at a huge event that is being livestreamed to millions of people rather that to have it shown at an Orchestra that's all about music and has a few thousand people recording it who would later go on to post their videos online. That is if people are even allowed to record the KH Orchestra.
They might show a teaser at the Orchestra, then show the entire thing at the conference. This is all speculation however.