Flights are still being made by UPS today, taking the route the phones have been which leads me to believe that UPS haven't shut down for the holidays and are still making deliveries.
Is that route not Shenzhen > Hong Kong > Dubai > Cologne > UK from what I've frequently seen people posting?
That's two Chinese regions which are officially on holiday and UPS has stated they are on holiday for three days.
Just because flights are still moving I wouldn't take that as gospel, an aircraft sat doing nothing isn't making any money so could still be carrying other goods or picking up in other countries etc.
The critical aspect is whether UPS are making pickups from Apple/Foxconn then processing it at the UPS airport hub before it goes to Hong Kong etc.
As I said, I just don't see it given how long its already been, but once again, I'd like them to prove me wrong.