Non-verified accounts on Twitter can still post, respond to posts, etc. I'm proposing that they don't allow this, and in fact simply disable replies altogether. It should just be a one-way announcement service.
Sounds to me like you want to build a platform that nobody uses
That's called a newsletter.
Exactly! That's all anyone really needs here. Official government accounts don't need comments from the peanut gallery (random people, who might not even be constituents) every time they make an official announcement.