Let's dump that and discuss what the Constitution really says. The First Amendment does not discuss "rights". The word isn't there.
What the First Amendment says is that Congress doesn't have the authority to restrict speech.
A corporation doesn't have to have "rights", that's irrelevant.
The Congress does not have the authority to shut the corporation up.
You can find no words in the Constitution giving the Congress this authority, ergo, it simply does not exist.