> If the NSA had that info, why go through the trouble?

To defend the optics of a backdoor that they actively rely on?

If Apple and the NSA are in kahoots, it's not hard to imagine them anticipating this kind of event and leveraging it for plausible deniability. I'm not saying this is necessarily what happened, but we'd need more evidence than just the first-party admission of two parties that stand to gain from privacy theater.