Almost, but not quite. Brandenburg created a softer standard than Schenck. The offending speech would have to incite or produce imminent unlawful conduct. But there's an exception for political speech in Brandenburg, which handed people back their right to protest against (and urge people not to comply with) the draft.
Alito claimed* that the 'fire in a crowded theatre' standard should be applied to today's college campuses, essentially because he has strong views on how free speech should/shouldn't be regulated at college. It seems to me that he's taking issue specifically with the right of students to engage in political speech and protest. The current court seems to have a particular distaste for case law from the civil rights era. I think he's deciding to bring this exact issue up because he wants to signal to any prospective plaintiff what rulings and precedents the court is likely to focus on in a hypothetical case. But he did that by deliberately misapplying the relevance of a widely-known and easily-misunderstood civil rights-era standard. It feels like he's doing that to taunt his political opponents and signal his preference for an earlier legal regime.
My point is that it's fair to question whether the court is actually behaving like a legislature: it's concentrating on case law that specifically affects social policy and it's doing that because it has a majority's muscle. As a foreigner, I can't explain how insane this looks from outside. Judges don't get to just show up to cocktail parties or speeches and single out the precedents they'd prefer to ignore or dispense with. That's a politician's job.
* https://lawandcrime.com/supreme-court/justice-alito-takes-di...
