This story has a meaningful message, and you don't have to overreach into economic analogies to find it. Sugar Belle tells us what it's all about.
"We gave up everything for you, because we thought you were our friend!"
The ponies in this village have come here because they each felt their individual lives were missing something important. Was it the common ownership of the means of production that they wanted? No, it was just friendship, harmony, and a sense of belonging.
"Is your friendship ending?"
Sugar Belle is genuinely confused about how friendships work. That's unusual for an adult pony, but it is not very unusual for the show's target audience of young children. Kids' friendships are often volatile, and some of them have not yet known a strong friendship that can weather an argument. Rather trivial disagreements can, unfortunately, signal the end of a friendship among children, so this is a realistic worry for some in the target audience.
It's likely that some of the adults in the village had friendships before they came here. I'm assuming that Starlight Glimmer talked them into doubting the veracity of those friendships, compared with her offer of friendship without judgment. Some of the other adults may have never had strong friendships before; they may have been ostracized where they grew up, and never really felt like they belonged anywhere.
"I'm sorry, I'm just having a hard time understanding. Different talents lead to different opinions which lead to bitterness and misery. So... why aren't you bitter, and..."
To gain harmony and friendship without judgment, the ponies in the village succumbed to a societal pressure which many of us have seen before. This is the threat in the story: the pressure to try to blend in with the majority, by suppressing those parts of yourself that make you unusual.
Some ponies may be more desperate to do this, because of pain they've already experienced from being different. Especially so if they've internalized the belief that they were at fault for being different, instead of recognizing that others were wrong to hurt them for it.
That peer pressure, to merely emulate others, is what this episode is about. It's not about communism, or socialism, or capitalism, or a mixed economy. It's not about any kind of economy. The story shows what peer pressure could do to everypony, taken to an extreme. Maybe we've all heard so much Cold War propaganda through the loudspeakers that it's hard to notice a message here that's not about geopolitics.