And we have a ruling in this case:

Holding : Petitioner, a private nonprofit corporation designated by New York City to operate the public access channels on the Manhattan cable system owned by Time Warner (now Charter), is not a state actor subject to the First Amendment.

Judgment : Reversed in part and remanded, 5-4, in an opinion by Justice Kavanaugh on June 17, 2019. Justice Sotomayor filed a dissenting opinion, in which Justices Ginsburg, Breyer and Kagan joined.

I agree 100% with the outcome in this case.