Why couldn’t the update start automatically once the wireless phone is sufficiently charged? That would not be hard at all to implement. Simply indicate the update is complete by making the phone beep until it’s removed from the wireless charger. Easy peasy.
I think the more challenging problem is designing a box that positions the phone in a way that it’s easy to charge wirelessly while still providing sufficent protection like packaging is supposed to do. Inductive charging has to be close to work well.