Hardly. Classical communism died out all over the west even in places without McCarthy, because people in the west could see what was really happening in the USSR and other places. The idea of having a revolution to replace the bourgeoise with the workers was tried, people watched, they saw it led to dictatorship and so it just got harder and harder to be an open advocate for that. "Deplatforming" had very little to do with it.
And really, communism didn't actually die. It just altered its terminology a bit, but the core ideas remained widespread. How do we know this?
Well, one reason is that academia is still full of people who claim to believe in Marxism:
https://www.econlib.org/archives/2015/03/the_prevalence_1.ht...
At least outside engineering subjects. So that's a pretty big hint it didn't really go away.
But another is that what we're seeing happen now is pure Marx. Divide the world into two camps, one that oppresses the other. Argue that the oppressed group is victimised, which is why it's the oppressors that own the assets and the wealth. Argue for fixing this with forced wealth transfers, forced replacement in positions of power. Then start to actually implement it, all backed by reams of impenetrable ideological texts, purges, witch hunts, show trials and so on. Claim at all times it's all about equality, even as deeply unequal systems are created before everyone's very eyes. Dare people to point out the double standards and attack them when they do.
We've seen it all before. The words change - proles and bourgeoise were replaced by black and white, imperialism with white privilege or patriarchy, and so on. But scratch the surface and you find Marxist arguments, still there, they never went away.
Why? Perhaps because anti-communists got intellectually lazy. The USSR and to some extent the Nazis made their case for them (Nazi being "National Socalist", lest we forget). Anti-communists didn't really have to build intellectual arguments for their case when the Berlin Wall was making their case for them.
But it's been decades since the wall fell. People haven't really been pushing back on Marxist arguments until very recently and even now, their intellectual muscles are weakened by inactivity. Meanwhile the Marxists have been camping out in academia for decades, brainwashing generations of students into believing - against all data and evidence - that the world can be neatly split into black and white, victims and oppressors. And now we're reaping the whirlwind.