Regarding free weekends: We know for a fact that all free weekends before September 2014 no longer affect these numbers, since that was the last time Call of Duty: Ghosts Multiplayer was free. Since the singleplayer and multiplayer are returning identical ownership numbers, all trace of the free weekend is gone.
Compare that to Advanced Warfare, which has 1.5 million Multi owners but only 800K single player owners, so six weeks on from its last free weekend (19th February) there is still a large discrepancy in the numbers.