This means you can't pass the game around to your friends or sell it afterwards, which completely ruins the purpose of physical media imo. I mostly play PC these days so this doesn't affect me, but it's a disappointing direction for console games. At least they could've used an empty disc that has proof of ownership.
EDIT: Bethesda has confirmed that only the PC version won't include a disc. Physical versions of Xbox will include a disc. Whew.
The fact the tweet this information came from has since been deleted could mean it's false info. We'll see if Godd Howard clarifies in the coming days.
Even if it includes a physical disk, it will most probably only have the launcher or a downloader on it.