I have some insight. UPS was horribly behind due to horrible mismanagement of these shipments. In Louisville, they prioritized 9/22, 9/23 & 9/24 shipments as they already screwed those people over, in an effort to catch up. They then promptly ignored all 9/25 shipments, something they would otherwise never do, probably so that they could catch up on other Air shipments.
There is no other explanation. On any other normal day with any other normal package, a shipment with 9/25 expected delivery that makes it to Louisville at 1 AM on 9/23 will be processed and shipped out within 24 hours to its final destination, with delivery on 9/24 somewhere between highly likely and guaranteed.
Instead, they are sitting on 9/25 packages. Delivery is indeed very likely for 9/25, so I have little to complain about....yet.
But I do enough shipping and receiving to know that my order should be here tomorrow, and won't be, due to poor handling by UPS.
...And I don't need to be a UPS truck driver to come to these conclusions.