Yip I believe from my flights that they've installed 2 x dual radio AP's rather than 4 x standalone AP's.

The decision to opt for 80Mhz channels is also a strange one - if any high density environment you really want to avoid duplication if possible, and 80MHz 3x3:3 channels really don't make a lot of sense in an environment when most clients (phones and tablets) are mostly all 2x2:2 radios. 40MHz would be a far better option.