This is a total misdirection that they brainwash you to believe. They are not a "Private company" they are huge multinational publically traded companies that must follow rules set down for business to follow.
Do you think for a moment if someone similar decided they didn't want to let any Muslims post on their site or any Africans or for that matter any democrats or homosexuals, that the news media, politicians and courts wouldn't be howling and out for blood with the courts soon to take up the mantle?
Look what happened when some baker told a homosexual couple that he would bake them a cake if they wanted but didn't want to do certain decorations on it because it went against his beliefs, but they were free to buy the cake and then finish the decorations up themselves or at another place. The state tried to destroy him and his business & he had to fight all the way to the supreme court on it.
These evil people are tricking you into thinking that their multinational empires are "private citizens" so they can discriminate against conservatives, Christians, men, hetrosexuals, freedom loving people. While at the same time demanding court and government action anytime somebody does a little bit of the reverse.
It's time to hit these technocrats with the heavy hand of Government regulation which they want for everyone else but think they are exempt from & see how they like it. Define them as public communication platforms and have the government enforce that any rules they make are all open, can be appealed to the courts & must be applied to every viewpoint and political side equally. See how they like it. If Google wants to shove "Gay Month" all over the place then they also have to accept running "Easter Week" or "Christmas celebration" just the same way.
(funny enough some Clinton loving judge just did that in reverse when he tried to make some weird logic that Trump's personal twitter feed was some kind of official public discourse channel & he couldn't block trolls and hatemongerers from posting on it.... Let me guess they wouldn't want that ruling applying to all the liberal progressive filth on twitter would they).