Regulation that dictate how a company may operate will naturally inhibit the consumers if the regulations is so heavy that the company will no longer exist. That doesn't mean such regulation is impossible.
The ban does not say that US citizens are not allowed to use the application (or apply speech). The method of the ban is similar to those blocking torrent sites, as in blocking them on an ISP level.
ISP already operating a fairly large block lists, both in the US and EU, blocking everything from pirate sites, scam sites, and more serious criminal ventures. The legal frame work generally do not talk about users (outside of deep packet inspection territory). They simply get applied more like industry regulation. It should be noted that the 1965 case has not prevented ISP block lists, and I would assume that the long list of pirate cases where ISP has objected to block lists in the last 30+ years has thoroughly tested the 1965 case. We can also look at the very recent net neutrality situation, where ISP has very much been defined as something very different from the postal service.
As a minor aspect being said in articles describing the ban, the ban would not prevent users from accessing the app if its already installed. As an ISP block it would break the functionality of the app, and new users would only get a spinning bar when trying to download it, but citizens would not be legally bound by the ban. That is mostly semantics but there is a legal distinction.