In O'Hare Truck Service v the City of Northlake, the Court's two most stanch conservatives (Scalia and Thomas) argued that Freedom of Speach protections are limited:@ParentsOf4 posted a dissent earlier from Scalia/Thomas where they disagreed with a first amendment ruling because they believe essentially in levels of free speech and that the government should determine what speech is appropriate. See the example below. So how is that related to this? If the same logic is applied, but instead of white supremicist group you sub in woke corporation you can see how dangerous this becomes when the government can decide which speech is free. I’m not saying the courts will rule this way, but if they did it would significantly change how free speech works for corporations.
The First Amendment guarantees that you and I can say and believe whatever we like (subject to a few tradition based exceptions, such as obscenity and "fighting words") without going to jail or being fined. What it ought to guarantee beyond that is not at all the simple question the Court assumes.
In Citizens United, the Court's four most liberal justices (Stevens, Sotomayor, Ginsburg, and Breyer) argued that Freedom of Speach protections can be based on the "speaker's identity":
“Our jurisprudence over the past 216 years has rejected an absolutist interpretation” of the First Amendment. WRTL, 551 U. S., at 482 (opinion of ROBERTS, C. J.). The First Amendment provides that “Congress shall make no law . . . abridging the freedom of speech, or of the press.” Apart perhaps from measures designed to protect the press, that text might seem to permit no distinctions of any kind. Yet in a variety of contexts, we have held that speech can be regulated differentially on account of the speaker’s identity, when identity is understood in categorical or institutional terms. The Government routinely places special restrictions on the speech rights of students, prisoners, members of the Armed Forces, foreigners, and its own employees.
We have both liberal and conservative justices arguing that Freedom of Speach rights are not absolute, that the Constitution provides only limited protection. Note that both cases involve corporations.
Citizens United is a 5-4 decision, and most of us are old enough to remember that it was (and remains) highly controversial. The news media in particular viciously attacked the ruling.
The current Court has not shied away from overturning precedent they believe was decided wrongly. Indeed, during his confirmation process, there was much hope that Gorsuch would vote to overturn Citizens United, if given the opportunity.
As you note, a decision from the Supreme Court could "significantly change how free speech works for corporations."