It follows my gestalt for Spread - that is, Centers slide away from each other as the Ends move into the vacated space. I would have no problem doing the above sequence - I would expect it to end with a facing box in the middle.

Whether it follows the Callerlab definition of Spread, I don't know. I haven't yet finished my definition of Spread, but here it is: http://www.ceder.net/def/spread.php

You'll notice that the 'From a diamond' example is the same as your 'as couples spread'.