Halo reach easter egg in campaign

So I was doing the 8th mission (with the falcon) in halo reach, when I had to go into the 2nd or 3rd building, and when I entered, I immediately recognized it as the map from Halo 2 called Ivory tower. pretty cool. It’s even got the fountain that has the sword in it in Halo 2. be sure to look out for more halo 2 maps in reach

That’s not an Easter Egg it was mentioned by Bungie in multiple videos and it is a multiplayer map.