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.”
That's actually a very good reason IMO.