N628AU,
You have to look closely at what Boyd actually said - "saying a merger or more alliances are possibilities". Not probabilities, not certainties, just possibilities.
As I also pointed out, he said that PIT "would serve as a key launching point to the West". With PHL, IAD, CLT, & ORD it is hard to see how a combined UA/US would need another "key launching point to the west" at PIT.
Jim