Another former UPS guy here for what it's worth:
It's the holiday season and routes are broken up and overlapped and lots of drivers are given helpers/runners to run packages from the truck for them, while they set up the next stops to save time.
It was common for a house call route to go from 100 stops to 200 stops between Thanksgiving and Christmas. Leaving a sign out where you want your packages is a great idea, since there's a good chance your regular guy isn't delivering your area and you have a cover driver with a helper working your neighborhood.
That said, after I left UPS, I'd be perplexed when I'd occasionally see a UPS driver leave a package down in my driveway leaned up against my garage doors, when I had a giant covered front porch just 5 steps up. The type of front porch that was every delivery drivers wet dream to leave a package safely on without much worry of what would happen to it, weather or otherwise.
