I know this isn't exactly what you mean, but if you look closely you can see a lot of gameplay features play like things in Reach did. The Titan lift feels a lot like the jetpack armor ability, the Hobgoblin shield thing is essentially just armor lock, pikes are similar to ghosts, the bubble shield was in Reach, and the Interceptor tank is like a one-seat Revenant with the Wraith's boost systen.