Except I doubt that's how it will work. They just have to get Apple and Google to bow to the pressure again and remove it from the app store. Restricting the first amendment is a lot easier if you can effectively do it without actually doing it officially.
Yes but if there's political/public support, Big Tech will sure jump in and get rid of their potential competitor.
Also, if the gov tries to ban it, its just open-soirce software, right? Haven't courts (in the US at least) ruled that code is speech, and therefore protected from government restrictions by the 1st Amendment?