If they figure out they need to go two directions at once with Halo 5, more CoD-ish with social play lists, and more CE/2/3-ish with ranked play lists, stop messing around with adding new junk in and focus on things such as UI, graphics, physics, and so on, Halo 5 CAN save Halo.
But they won’t figure that out.
They’ll either go even further into the codification of Halo, rehash Halo 4, or least likely go back to CE/2/3 Halo core game play. (Which would make me ecstatic but it wouldn’t be as popular as Halo 5 could be).
Halo doesn’t need to become CoD: Halo.
Halo doesn’t need to go back to being more like CE/2/3 either.
It needs BOTH.
It needs to have Social and Ranked 1-50 playlists just like 2 and 3 had. The social play lists need to be CoD: Halo basically, and the ranked 1-50 need to be even more like 2 and 3 than 4 is.
The campaign should be some mixture of the two probably.
This would make Halo 5 appeal to the new CoD players who enjoy mess like perks, aim down sights, kill streaks, etc., but also keep Halo Halo, and perhaps even show those new players why the old real Halo game play is better than CoD game play. If they played the codish social Halo a lot, they might eventually start to like the ranked CE/2/3 style 1-50 Halo better.