I think an awesome addition to the older titles would be the Team Takedown medal from Halo 5. The medal is awarded for when you kill an enemy player assisted by 3 or more teammates. The main reason for the suggestion is when new or returning players try Halo I often hear complaints about kill stealing. I believe the medal would benefit team comradery and increase retention. I wonder how difficult from a technical aspect it would be to add?It maybe could find its way into Halo 2 Anniversary but that's it. Or maybe 343 can add it in as part of the unified medal system that runs in the background with CE and H2. I'd like it to stay out of the default/classic medal system for each game.
The classic style/system for any game from the past will always have its advocates. Rightfully so I might add. But, I compare it to any physical sport or game like baseball, football, or basketball. Well designed and thought out changes can improve the experience tremendously. Halo 3 out of the box was a masterpiece for the record books. With consistent small additions I hope Halo 3 Infinite
will be a game many of us will be playing for decades to come.
Also, an important contrast of physical and digital is custom experience for each individual.