It doesn't answer that, it can't because the replicator is fictional. McFarland just says he wrote an episode in which his answer is that replicators need communism, and then claims that you can't have a replicator in a capitalist system because evil conservatives, capitalists and conspiracy theorists would make strawman arguments against it.
Where is the thought provoking idea here? It's just an excuse to attack his imagined enemies. Indeed he dunks on conspiracy theorists whilst being one himself. In McFarland's world there would be a global conspiracy to suppress replicator technology, but it's a conspiracy of conspiracy theorists.
There's plenty of interesting analysis you could do on the concept of a replicator, but a Twitter thread like that isn't it. Really the argument is kind of nonsensical on its face because it assumes replicators would have a cost of zero to run or develop. In reality capitalist societies already invented various kinds of pseudo-replicators with computers being an obvious example, but this tech was ignored or suppressed by communist societies.
Communism as it exists today results in authoritarianism/fascism, I think we can agree on that. The desired end state of communism (high resource distribution) is being commingled with the end state of communism: fascism (an obedient society with a clear dominance hierarchy).
You use communism in some parts of your post to mean a high resource distribution society, but you use communism in other parts of your post to mean high oppression societies. You identify communism by the resource distribution, but critcize it not based on the resource distribution but by what it turns into: authortarianism.
What you're doing is like identifying something as a democracy by looking at voting, but criticizing it by it's end state which is oligarchy.
It takes effort to prevent democracy from turning into oligarchy, in the same way it takes effort to prevent communism from turning into authoritarianism.
Words are indirect references to ideas and the ideas you are referencing changes throughout your post. I am not trying to accuse you of bad faith, so much as I am trying to get you to see that you are not being philosophically rigorous in your analysis and therefore you are not convincing because we aren't using the same words to represent the same ideas.
You are using the word communism to import the idea of authortarianism and shut down the analysis without actually addressing the core criticism McFarland was making against capitalist societies.
Capitalism is an ideology of "me," and if I had a replicator, I would use it to replicate gold, not food for all the starving people in Africa. I would use it to replicate enough nuclear bombs to destroy the world, so if someone took it from me, I could end all life on the planet ensuring that only I can use it. So did scarcity end despite having a device that can end scarcity? No. Because we are in a "me" focused stage of humanity rather than an "us" focused stage of humanity so I used it to elevate my own position rather than to benefit all mankind.
Star Trek promotes a future of "us" and that is why it's so attractive. McFarland was saying that "us" has to come before the end of scarcity, and I agree with his critique.
The reason these two ideas get commingled is because in practice they're indivisible. A high redistribution society requires high degrees of coercion and fascism.
To get around this the usual Star Trek analysis (by fans, the series itself doesn't talk about it much) is that after replicators were invented, there didn't need to be capitalism anymore and so there's no money in the future and everyone just works on perfecting themselves. It's a wafer thin social idea that was never fleshed out because the writers themselves didn't believe in it. Roddenberry insisted but the writers often couldn't make it work which is why there are so many weird hacks, like saying the replicators can't replicate things as big as star ships and they mostly just ignore the whole topic. Also the replicators kill a lot of drama because they mean there can't be any valuable objects.
There are obvious and basic objections to this idea that replicators = communism (in either direction). One is that you can't replicate services, and much economic activity today is the service economy. We see that the Enterprise has staff who do things like wait tables, cut hair and sign up for red uniform missions in which they will surely die, but why they do this in the absence of money is never explained. There's just this ambient assumption that everyone works because work is awesome.
Getting back to the thread, the lack of philosophical rigor here is all on McFarland unfortunately. He doesn't actually have a critique of capitalism. He doesn't even seem sure what capitalism is, appearing to use the term to just mean contemporary society and anyone he doesn't like. Even his arguments against his strawman enemies are garbled and useless! He shits on Musk, saying that if Elon invented a replicator he'd patent it and hoard the tech to himself, ignoring that Tesla gave away its entire patent pool so anyone else could build electric cars using their tech. Musk - arch capitalist - did the OPPOSITE of what McFarland claims capitalists do, and he didn't even notice! All the rest of his argument is also like that. He makes absurd claims about governments, Republicans killing animals in TV ads, some non-sequitur about meatless sausages ... it's just this total grab bag of incoherent thoughts that make no sense and don't seem connected to each other, wrapped as "capitalism sucks, communism rules".
If this were an essay I'd grade it an F. But in the end it's just a set of tweets. Those looking for philosophical rigor on the idea of an abundance machine need to look elsewhere.
Where is the thought provoking idea here? It's just an excuse to attack his imagined enemies. Indeed he dunks on conspiracy theorists whilst being one himself. In McFarland's world there would be a global conspiracy to suppress replicator technology, but it's a conspiracy of conspiracy theorists.
There's plenty of interesting analysis you could do on the concept of a replicator, but a Twitter thread like that isn't it. Really the argument is kind of nonsensical on its face because it assumes replicators would have a cost of zero to run or develop. In reality capitalist societies already invented various kinds of pseudo-replicators with computers being an obvious example, but this tech was ignored or suppressed by communist societies.