They never said that they were going to make a separate multiplayer. They told us straight up that it was going to be Reach's multiplayer but with some tweaks that make it play more like Halo, although that's what I noticed for every video I saw.
And it definitely a remake of Halo 1, they kept everything from the first one, only some glitches that are impossible to do because of the 360 memory. All they actually did was add some Kinect features and revamp the whole entire game's graphics, which are absolutely beautiful, as you said.
Although I do agree with you that multipayer would of been a beautiful step up, but I'm extremely happy with my purchase.