Thought I'd ask, as seeing as how characters such as Lucio, D.VA, etc were never actually official members of Overwatch before its disbandment, how would they be introduced to the team? Personally I had the idea that during his "retirement", Winston, along with the help of Athena, kept track of talented individuals such as Lucio and D.VA, making use of an algorithm that added such people to the "Recall Roster" or something. 

Of course that's just one idea :P