User blog comment:Damac1214/Back in Black - Call of Duty: Black Ops III teased, reveal trailer coming April 26th/@comment-4117054-20150410010705/@comment-1916935-20150412222837

I don't think that would work very well. Some endings have Menendez dead, either by suicide or by Mason, some endings have the White House burning, some have the Celerium worm working, some don't. Those seem like pretty big plot points that would be pretty difficult to have them all reach the same point eventually.