One of the biggest knocks against Deus Ex: Human Revolution was the way in which boss fights forced an aggressive playstyle. According to Eidos Montreal, that won't be the case in Mankind Divided.
In response to a fan question on Twitter, executive game director Jean-Francois Dugas responded that Deus Ex: Mankind Divided will be completely ghostable, boss fights included. That means stealth is an option for the entire playthrough, unlike Human Revolution.
Deus Ex: Mankind Divided also includes an extra hard mode called "Give Me Deus Ex," which encourages even more stealth for players who truly want to play the game without alerting anyone.
No release date has been announced for Deus Ex: Mankind Divided, but it's in development for PC, PlayStation 4, and Xbox One.