The music sounds like a slightly muffled version of 'Khans of New California'.
Sure brings back memories though. I remember how excited I was to find the minigun in the fridge in the public demo.
I was actually the one who posted the Fallout Nerd question.
I assumed that Operation Anchorage was the initial attack on Chinese lines in the late 2060s, thus only having T-45s, but if this is rather the final push, yeah the T-51s would be in service (albeit with limited numbers) at that...