How much precedent is there for this? Are there parallels for other countries? Does the US prohibit any news agencies from operating in our borders? Does Europe? Does Russia? Does China? I presume North Korea does, but I don't actually know. These aren't designed to be leading questions. I don't know the answers, and rather than searching, I figured someone else here might know offhand.
RT was heavily censored in the USA and is banned in several European countries. Press censorship is pretty much the norm in 'western democracies' similar to everywhere else.
All countries are on a spectrum, there is no clear line between shiny democracy and brutal dictatorship. They all have institutions that look similar on the surface. A democracy is not going to stop having a police force just because some police states also have one, for example.
So yes, some democracies ban some media spreading propaganda for foreign interests, but the details matter.