Sega did the exact same thing when they released the PC version of Sonic Adventure for the consoles but they ripped out the DX stuff and sold it as DLC.
Yeah but I don't think they announced it as the DX content before hand (like they have with FFX/X-2) nor did they have a previous track record which SE now does (with KH1.5 HD being the FM versions)
This is just very unlikely to be true, the Last Mission stuff is the only bit I can see being true because as I found out in another thread, it was basically a separate not part of the main game addition.