Will the flood ever return?

I kind of hope so. While they were one of the most annoying enemies in the entirety of gaming (owing to the fact they took over the ends of CE, 2 and 3) it would be nice to see the flood reimagined with the next generation of consoles.

I believe there are numerous other discussions about this.

There a Chance the flood might return but if they continue the halo saga

there are rumours that the flood will appear at the end of Halo 5

there a big chance of the flood to reappear in the books it explain the infinity made contact with the spirit of fire were they damage the infinity but were kill afterwards and the spirit of fire was drifting to an unknown planet carrying floods spores around the ship

I’m willing to bet they’ll be back in some form.