I realized that the man cannon isn't as new as you may think, remember the grav lift on Ascesion, pretty close don't you think?
Yes, they're in Halo 2... Ascension... Gemini... Desolation... There might be more but I can't think of any, I'm tired.
Yeah, also there are also the lifts on Ivory Tower and Worlock, but they are much like the grav lifts of H3. The difference is what they moved between you. In h2, it was to reach higher levels, ascension included, where as in valhally and narrows they move you across the map, the way teleporters do.
Yah, I was just realized that grav lifts from the past games and man cannons were a little bit closer than I thought, not that much though...