I'm afraid that you are too optimistic. While, as mentioned in the story, communsim has become a very dirty word, with the CCP even changing their name, socialism remains and I have little doubt that they'll clinge onto Bolshevism.
Who is "they", though?
We know of all of the crimes that the likes of Lenin, Stalin, Pol Pot, Mao and countless other communists did. Yet this does not stop prominent academics from supporting those scumbags. Communism is a scam, designed to let wealthy, educated people with no real power to take that power, using the poor as cannonfodder. As such, there are simply too many interest groups who'd like to keep the ideology. All those people will probably try to rebrand the Bolsheviks as socialists, to get away from the stigma of communism, but I wouldn't count on them actually changing their policies or acknowleding that they did anything wrong.
Based on current trends, I'm leaning rather that the TTL communists will try to lie outright and flagrantly about how Russian Bolshevism was actually a far-right ideology that has nothing to do with actual perfect communism.
We can see reflections of that trend in OTL and the attempts to rebrand Stalin as some kind of "right-wing paleoconservative who was completely ignorant about Marxism and communism" because such people resent that Stalin re-criminalized being LGBT in the USSR later. that Lenin abolished those laws...
I think that the one factor that you both overlook is the extent to which these crimes are not just contemporary but global. It is not a matter of atrocities committed a couple of generations ago but of crimes being committed in full view of the world, around the world even with the final nuclear spasm. To an extent that I think has to be appreciated, everyone alive on 4/10 has deeply relevant experiences. The only thing OTL I can compare this to is the way that 9/11 was a polarizing global experience, but even this comparison falls short because the worst damage was limited to a relatively small portion of one city.
I think that the closest comparison might be to the former Yugoslavia in the 1990s. In that case, you did have some people who actively supported Serbia and Serbian nationalists, some in the left because they let their nostalgia for the Titoist alternative and their dream of a different world without Western hegemony overcome their good sense, some on the right because they approved of the killing of Muslims. (You can see, re: the latter, faint echoes of the next decade's Eurasia theories.) Others were simply nostalgic for past friendships between Serbia and their country.
The fatal issues that these encountered is that very few people outside of these circles agreed with this. People on the left might have wanted a different utopian world and people in the right might have been hostile to immigrants and/or Muslims and/or ethnic minorities, but to an overwhelming extent they disapproved profoundly that mass killings and war were the way to handle it. There were many people concerned with old friendships, but trying to play upon past friendships to justify one's own crimes was not a tactic that worked anywhere outside of Russia, there because of Russia's own resentments at how the 20th century turned out. People were not invested in this.
There is definitely going to be political radicalism in the future; there are too many inequities in this world, as in our own, for this not to happen. The post-4/10 political centre is going to decline in Western countries, too, as memories diminish. What I feel confident in saying is that, outside of certain minorities utterly disaffected with regular politics, the Soviet example will be one that will be shied away from. For generations, the fear shared worldwide that a Communist regime heir to the Soviet Union would end the world is not going away.
Beyond that, there is the matter of practicality: Ignoring everything else, the Soviet system just did not work. Sure, you can go all edgelord about the Soviet system in the way others might about the Nazi system, but ignoring the limited reach of edgelords why would someone looking for a better future look to something that resulted in catastrophe?