There will be cutscenes, surely. No way they will make a story-focused 20-hour game without a single cutscene.
They already said there are no cutscenes.
There are story scenes but there is never a single cut in the whole game, the same camera begin and finishes the game without ever being cut for another shot.
Also it's said to be over 30hrs long.
OT: SM may be about to set a new standard way to present games, sounds cool.