Context: There was a theory going around that Efi has / would die sometime in the Overwatch story, which is why Orisa is now an Edgy Murder Bot.
Since Orisa said recently, I’m assuming Efi is still alive and something else made Orisa this was, such as firsthand experience fighting Doomfist, maybe with some other civilian casualties, or the pressure put on her by this encounter.
They wouldn’t add her into the game because killing a child is problematic. Why would they then kill her in the lore? 
Lore?
They seem to be fine with “30,000,000 Orphaned Children”. Why not use children as a motivation instead, like with Ana, but in a more severe case (somehow).
Of course Efi is still alive. Nothing indicated that she wasn’t. Orisa has a more mature personality now because time has passed and she now has experience that she didn’t have before.