Essentially, the new law will mean that storefronts like Steam will no longer be able to use terms such as “buy” or “purchase” when advertising a game that always requires an online connection. Since you won’t technically own the product and servers being taken offline would render the product useless, a different word will have to be used.
The official phrasing in the bill’s summary reads, it will “prohibit a seller of a digital good from advertising or offering for sale a digital good, as defined, to a purchaser with the terms buy, purchase, or any other term which a reasonable person would understand.”
To be honest, it sounds like it would affect ALL digital products, not just those requiring an active online connection. Or at the very least even those with Steam DRM for verification.
I don't see why there's a distinction for always online games. You don't "own" any game you buy off steam. All you get is a license to play the game off steam. You can't sell or trade them.
Even if you buy a DVD, the only thing you are "buying" is the physical media and a license to operate the softwate. You don't own the software stored on the media, you must use it in accordance with the license agreement or potentially face legal action. The main thing about digital storefronts is that it's easier to revoke the license.
If you buy a movie, you are buying the rights to private use of the movie, you aren't buying the copyright. You can sell a DVD movie to someone else and it's not illegal and doesn't subject you to copyright law.
If you buy a game that has a license key, then yeah, you are buying a license to the game even if it has physical media, but buying a physical copy of an Xbox game doesn't have a license key (well, more recently they do, the box contains a store key instead of a disc, but before that was common practice)