Shortly after the Disney’s $71.3 billion acquisition of Fox assets officially closed at 12:02 AM ET Tuesday, the deal’s architect, Disney CEO Bob Iger, sent an internal memo to the incumbent and newly added company employees titled “A Historic Day for Our Company.” In the note, Iger outlined Disney’s plans for the future, stressing its focus on building its straight-to-consumer business. He also warned of “the challenging work of uniting our businesses” that lies ahead…