Easily has the potential to be one of the best flex support heroes in the game people just need to learn how to use her and then maybe some slight adjustments. One idea I have in mind is giving her a slow (Lucio speed) self heal that you hold down to use (while holding it down you are unable to attack or use any abilities) that way if you want to heal you don't have to waste your grenade which is extremely helpful in team fights.
Also just saying I called it. Ana is by far the best offensive flex support right now. Best defensive flex is Zenyatta in case you were wondering.
From what I have heard Sombra the supposely new hero to be introduced to Overwatch will be shown at some sort of games con for Blizzard or at the end of Season 2 of comp.