Not sure that this is true. The Supreme Court in recent years has smacked down several regulations on free speech grounds in surprising ways. Campaign finance reform (aka "Citizens United") isn't a popular one on the left, but it's an example of deferring to the first amendment even when regulation has good intentions. Another case was the FDA regulation of off label marketing of prescription drugs. The crux was that you can't tell certain people (sales reps) that they aren't allowed to talk to other people (doctors) about objective facts.
The two cases you cite have big differences from the "extremest narrative" that prompted this submission and alone are not a good thermometer for how the court will rule regarding speech in general.
Both cases regarded speech that is already highly publicly tolerable. Sure people may moan regarding the level of rhetoric some in political ads, but it's ultimately just because they're lying. The FDA case is similar, objective facts known about drugs communicated between professionals in fields related to those drugs isn't distasteful to the public.
Both cases were about otherwise-legal speech that was restricted in a narrow business context. Citizens United overturned a finance rule, not Pacifica. Those ads could have been shown before Citizens United if they were funded differently. Doctors could already learn about off label use outside of a sales call.
The circumstances around the speech are important to the court. While I see no chance that regulations on religious hate speech would go over at all (especially not once the Christians realize it would apply to them too), the legal reasoning would probably not draw from either of those as precedent.
If the court actually were to issue surprising rulings on free speech, they would have found in FCC v Fox that Pacifica's "uniquely pervasive" rationale no longer held.
One wouldn't be too hard pressed to make the argument (although I won't) that those cases are examples of the court being business-friendly rather than broadly speech-friendly.
