Source: Halo4newsConfirmed on the Halo Waypoint forums, the Flood will not return in Halo 4.
Question – Do you think the Flood may return as the Precursors’ servants? I’m guessing this with the hints in Primordium. What do you think?
Response by Frankie – You won’t be fighting Flood in Halo 4.
Frankie might be better known as Frank O’Connor, the Franchise Development Director for the Halo franchise at 343 Industries.