Meta modernism is essentially the second reboot of Marxism. As soon as a few get wise we'll see the emergence of Post metamodernism or some such.
I don't think it's helpful to call it Marxism, or even to think of it in those terms. Do you mean that metamodernism is the reaction to liberal individualism (the dominant paradigm)? I think it is as well. But there's a major and critical difference. I'm using the term "Marxism" in the sense that USSR and 20'th century communists used it. Not the liberal arts academic use of Marxism (which was different).
Marxism and collectivism aimed at replacing the the individual with the collective. The idea was to create a kind of super individual. A collective with one will and one voice. So individualism had to be subjugated.
While metamodernists are more collectivist. They're not placing the collective above the individual. Metamodern collectivism is more an acknowledgement that humans are inherently collectivist. We are always a part of collectives. They shape us, form us and define who we are. It's an acknowledgement that claiming that we able to rise above the influence of others is just childish.
I think the South East African philosophy of Ubuntu catches what I mean very well.
https://en.wikipedia.org/wiki/Ubuntu_(philosophy)
You don't know who you are until you see the effect of your actions on other people. You and your identity is made by other people...and you make them. Your view of yourself will change depending on how your actions affect other people. If you are moved to a new context your sense of self and identity will probably change.
It might be good to delve a bit into history of philosophy. Liberal individualism is what Marx reacted against. But it was different from today. It was 19'th century romantic ideals holding up the lone genius, artist, scientist or political leader, who by sheer force of character, rises above any influence and shapes history. We are all either a leader or a follower. Hegel put geniuses in front of each ideological movement. His thesis, antithesis and synthesis. Napoleon can be seen as a good example of this (or Hitler or Churchill). What Marx did was to keep the model but just remove the genius. No, it's not geniuses who shape history. It's other stuff. Money, technology, lack of security, mass hysterias, rumours and so on. He made Napoleon as just an opportunist. Napoleon didn't make Napoleon. His context did. Anybody in Napoleons situation and context would probably have turned out similar and made similar choices.
Marx wasn't inherently collectivist. He was too early a thinker. His view of the collective was more Rousseauist. You could say that Marx himself wasn't Marxist (using the term define at the begining of this post). Marx believed that with the removal of power structures we'd return to some unspoiled pristine state of pure goodness and kindness.
Marxist/fascist collectivist theory were shaped by, now largely forgotten philosophers, like Sorel, Barres, Herder, Haeckel, Herbert Spenser and so on. I think Charles Darwin was a bigger influence on these people than Marx. The ideas of social Darwinism in particular. These saw history as the war between collectives. The more organised and singular in their goals, the more successful will the collective be.
The current paradigm, liberal individualism. Is a reaction to this. But they replaced the lone genius with, (the nebulous concept) everybody's equal value. And that if we only give people equal opportunities they will shape their life in whatever way makes them flourish the most. People are different and we just need to get out of people's way and let them explore themselves and their world freely. The less we try to shape and control people the better. Instead we "educate". Within this paradigm telling anybody what to do is pure evil.
Note, I now risk putting words in the mouth of Metamodernists, and conflate their ideas with mine. I apologise if I give that impression and are trying not to. My interpretation of metamodernists is that they agree with that we're usually better off just getting out of people's way and let them shape their lives as freely as they can. They just question if it's possible to shape it freely.
They also reject the idea of everybody's equal value. If you're lost in the middle of nowhere without reception, a passing taxi is more valuable to you than anything else. Unless you haven't got any money. In which case just a car driven by someone friendly is worth more to you. Or if you are bleeding to death an ambulance. Your changing needs will lead you to value other people differently. It's not an inherently elitist view. It just questions the vapid claim that all people have equal value. We clearly don't have equal value. There is no inherent worth in human life that we don't give it. And we have never behaved as if we thought every human life is equally valuable. We all treat our friends better than non-friends.
Our human value is based on our context/collective and our capacity to figure out a way to be useful to that context/collective. In that way metamodernism is collectivist. But one huge difference is that the Marxist or fascist collective is something you are born to, or something inevitable or essential. It's also singular/monolithic, and your only choices are to be "with us or against us". This type of collective justifies force if you aren't part of it.
The metamodern collective is more free flowing. Collectives aren't eternal. They spontaneously emerge and disapear in the meetings of people. Collectives only stick around if they are continually useful to the individuals it comprises. While you are part of a collective your feelings, thoughts and emotions are still just stuck inside an individual. Those will be paramount to you. If a collective isn't working out for you, then you pick another. Also, we don't have to make an effort to form a collective, and we don't need a committee to figure out the will of the collective. Collectives form spontaneously and their borders are amorphous. A collective is whatever it's members do.
A good example I think is Christianity. Christianity is one collective of sorts. There's loads of denominations. Those are all collectives. Not necessarily in conflict with other Christian denominations. Then there's your local church. Your group of friends within the church. Even if you never go to church, if you are a Christian you are in some way part of the Christian collective, just based on interactions with people around you. Chritstian and non-Christian. Your sense of belonging to the Christian church will shape your behaviour in some way.
I think metamodernists maintain that the idea of people as being a detached sea of liberal individuals rationally picking and choosing what suits them best, is a lie. This forum isn't a collection of free individuals posting. This forum is a collective where our actions are shaped by how our posts are read, received and responded to. If we wouldn't get the responses we need, we would leave and find another forum, or another way to nurture our needs.
