I remember reading somewhere that 343i said they’d use Halo 5’s gameplay as a base for Infinite, and it looks like that’s exactly what they did. The AR is very similar in each game, and the gunplay seems to be as well.
It does look like 343i is giving themselves more creative freedom in the campaign with the addition of so many new pieces of equipment.
All in all the gameplay demo looked amazing, and I can’t wait to see more.