Because if it were EvilDragon would have mentioned it. Instead he's been talking about the complexity of designing such a thing and the amount of reworking Nikolaus has had to do.
The compute module exposes all the pins of the BCM2835 but the OMAP5 has a different set of I/O, it wouldn't make any sense to try and make them compatible, there would be sacrifices.
Further, at 30mm it consumes a lot of board space, Nikolaus has worked hard to make the Pyra's CPU board compact so that it doesn't change the Pyra's dimensions nor get in the way of the keyboard.