Agree with everything, just wanted to add that whilst Halo 4 had a 70-80million user install base within which to risk the longevity of the title, and risk they did in the worst possible way, it seems they're going down a similar path but this time MS/343 will have to contend with trepidation from what is left of the core fanbase, and a much smaller user base within which to (shamelessly) front load sales, longevity be damned.
Pretty big risk they're taking IF they attempt to implement more flavour of the day mechanics. It'll be a shame, but hopefully they'll take note of Halo 4's rapid post launch drop off....and not blame it on the game not being CoD-like enough, which I fear was/is/will be the decision makers' reasoning for H5. Time will tell.