I thought that Facebook's stance was that it was a platform not a publisher? If you have no editorial oversight or opinion on the content you publish (cf. not taking down known false political advertising) can you then claim "free speech"?

Similar warnings are required on cigarettes, and there isn’t much difference between the two.

Did you read blunderkid's comment? He's much farther into "opinion" territory. I don't think he's stated a single fact.

When did the court rule that cigarettes constituted speech?

They didn’t. They ruled corporations don’t have much free speech when it comes to product advertising and declarations of potential harm their products may cause their users.

> there isn’t much difference between the two

Can you post a link to RCT-based evidence backing this claim? I don't see anything on CDC website or any professional medical organization about Facebook being as harmful as cigarettes.

Commercial speech is heavily regulated.