You know what.
I wouldn't be surprised if this game has something like Witcher 2. Where the hardest difficulty is so penalizing that you had to restart all over again. But with a game that has so many hours in it, I personally do not see it to be part of it. Just because, Witcher 2 was such a small linear story. I am at a point I could care less if they add difficulties like that. I had my fill with that part of Witcher 2 and it was so crazy, in someway was very interesting because you had to figure out your enemies moves and counter attacks. I end up achieving the award as "madman" for completing the game on insane.
One thing I find it kind of odd with applying such "insane" mode to this game is the demand of ways to mitigate the game itself against npc's and even dialogs? Is not like Witcher 2 that was very linear with its own written scrip that only affected gameplay. And that is why Witcher 3 never had it, wasn't implemented. Because how long that game was. That is why I think the game won't have an "insane" kind of version. If it does I would be super surprised, given that it is an open world, less than a linear.
Haha, imagine walking dow the street and getting hit by a car... restart!