I severely doubt that will even happen, 343 have had years to work on such a thing for the original. I really want Spartan Ops Matchmaking to return as that was in the original on the 360 version.
What makes you doubt it? We are already seeing previously forgotten unfinished content being released next season. Wouldn't it be easy to record a couple of voice lines, drop some enemies in one of the campaign levels they reused (multiplayer maps could work too) and then have a few hours of content produced for relatively few resources. Sounds like a slam dunk for 343 to me.
Yeah, just shell out to get all of the cast back, syphon some devs from other facets of the project (like bug fixes), contact Axis Studios to make new cinematics, etc; all in what reads like an otherwise lazily presented rehash of existing content, for a game that came out 8 years ago, in a mode the player-base didn't care enough about for it to be continued in the first place, whose entire narrative direction has since been concluded, altered or nullified by Halo 5's Campaign and expanded material.
They'd be much better spending the resources on extensive mod tools and implementing
actual near-finished cut content (Silenced SMG from H2:V,
Blast and
Concrete weapon skins, the H4 '
Revenant', hopefully the Halo Online exclusive maps, etc.) since they fall within the range of things that people actually care about and are technically feasible.
