The advantage of outsourced call centers is that people go by the book, not by common sense.

So when I needed 4 seats in O opened up due to a sked change, a US-based agent would take a look at F4 and tell me to come up with a different routing. An outsourced agent instead looks at UA's policy on sked changes (if UA's responsible for sked change, they should open new inventory), and cheerfully provide last seat availability.