Thanks to Brendan for bringing this to your humble host's attention.
Wizards of the Coast functionary Bruce Cordell has written here and here about how 5E backgrounds are all awesome and can permit character concepts such as a wizard who is also a spy! No mention is made of John Holland, whose The Realms of Atlantasia expertly developed that possibility previously. Given D&DNext's tendency to emulate Holland's design, it seems Mike Mearls is worried about the threat posed by Atlantasia after all.
John Holland's attorneys were not immediately available for comment.