Eidos has confirmed that Deus Ex Mankind Divided will let you play the whole way through without killing anyone.
This was confirmed by executive game director Jean-François Dugas on Twitter:
— Jean-François Dugas (@Jeffachoo) April 11, 2015
One of the chief complaints from Deus Ex Human Revolution was that it strayed from the series’ conventions by compelling you to kill the bosses. While Eidos did explain this is partly to serve the game’s lore, obviously this has been changed for the new game.