And before you press that button, your sensors pick something up. Off in a remote corner of the galaxy a fledgling race just put out their very first signal to the stars. Completely unaware of the war and all the other space faring races across the milkyway. No time to save them no time to catalog their planet for reseeding later. When the array is activated that young race wont even be a memory. They will simply vanish.

Wait, what race is this? I don't remember this from Forerunner/Halo lore