Halo Reach maps with Halo CE:A
This is my understanding... With the Halo CE:A disc I have access to the Halo Reach infrastucture but I can only play the Anniversary Maps. I dont have access to the Halo Reach maps.
With a new Halo CE:A disc you get a code to redeem the Anniversay Map on Halo Reach Disc. So if I use my Halo Reach Disc and I have redeemed the code I have access to Reach and Anniversary maps.