The post WW, Cold War era was marked by the federal government, senators and intelligence agencies literally maintaining lists of “communists” that were blackballed almost entirely.
Oppenheimer was released only recently, a movie which is all about how a tenuous communist connection led to the demise of the career of among the most famous scientists in WW2.
Students were famously killed for protests in Berkeley just a few decades ago.
And it’s only been a few decades that anyone but a white man was even allowed on campus.
The idea that speech on campus is anyways more restricted than it has been in the past is ridiculous on its face.
The idea that speech on campus is censored any more than in the past is very clearly not true. What might have changed is either the groups of people whose speech is curtailed has changed slightly, but more likely, you tend to hear a lot more about it because of social media.