According to a screenshot from Twitter user @VG_Dave, Square Enix has cancelled all digital PS4 pre-orders for the upcoming Hitman title:
In response to the tweet, Hitman Community Manager replied back, clarifying the situation (at least in terms of release date):
@VG_Dave Don’t panic. We’re adjusting a few things and will update in a few days. The release date is still March 11th.
— Travis (@IO_Travis) January 13, 2016
While no reason was actually specified, one possible conclusion could be that the game might be simply released as a whole title digitally, instead of the episodic method that is currently in place.
Of course this is merely conjecture; we should receive an official reason for this situation soon.