i thinnk a cool thing iin halo infinite would be music disks from every halo ost or certain songs from it hidden in little areas arouund the map like reach ost songs are on reach and halo ce osts on zeta halo and stuff like that. because who doesnt wanna beat up the banished while listening to that halo 2 nostagia 
ALSO if you collect all of them you get a rare achievement named iconic
Totally in favor of this idea.