I personally wouldn't want 343 Industries spending any time whatsoever on ports of old Halo games. Not even from a QA perspective. As long as there isn't some kind of new scenes being added or retconning being done, there's nothing really that should impact the Halo canon that 343 has inherited or any of their current projects. Keep these guys focused on Durango Halo.
But again, people assume that Microsoft (or any large company for that matter) doesn't just have shit poor internal communication and sometimes higher level execs who want to feel important with ludicrous amounts of secrecy from their own staff. They do. Who knows if this is a case of that?