An Easter Egg (or perhaps just a graphic) was noticed during the Tech Preview that shows John-117 on a poster with the Blue Team insignia in field, and the text “BE A HERO - John-117 Petty Officer of the Navy.” This presents some problems, as I see it.
I’m hoping this isn’t a continuity error as currently present with what we know of the Mk VII armor kit (screwing up the numbering sequences). Firstly, the rank is Master Chief Petty Officer of the Navy. It’s an Advisor role, spending most time observing training and talking to sailors and their families. Not really a role fit for a Spartan. Secondly, MCPON isn’t a rank in the UNSCDF per the Spartan Field Guide. Third, John-117 was never promoted to MCPON, and after his AWOL escapades in Halo 5, I sincerely doubt that he would be promoted, or accept such a promotion.