Eh, sorta but not really. Socialism vs. Capitalism is defined based on who controls the means of production rather than discreet policies. A state with a robust social safety net, as Megaton seems to be turning in to, will still be capitalist and subject to the inherent contradictions of capitalism so long as the capitalist class is still the owning class.Socialism and Capitalism aren't necessarily opposed. You can have a Socialist Society where everyone's basic needs are met (food, water, shelter, and healthcare) but it can also be Capitalist in that more luxurious items can be worked for and purchased. Want a bigger fancier house? Find a job, earn currency and purchase one. Want something fancier than the government supplied food? Buy it.
Plus, a market for arts, crafts and handmade items would likely form. As an example, in Star Trek, a person can go up to a replicator and order an alcoholic beverage, but Picard's family still run a vineyard because there's still a want for alcohol made in the old ways. Home cooked meals are still a thing, restaurants still exist, etc.
That's something Lily needs to realize, her old Anarcho-Capitalist station worked because of the technology involved, everyone was a Post-Human Cyborg or a full-on Uploaded Mind with access to the knowledge and technology to be fully self-independent. Something not true of Fallout, given it does have the technology but it's so rare and hidden basically no one knows it even exists, and even then, they wouldn't understand it. And most Wastelanders are too busy trying to survive to sit down and study Pre-War technology to try and build a 'better' society.
I agree with you that Lily's ancapistan was only possible due to tech advances, though. We've seen what happens every time lolbertarians try to make their perfect society, and it never ends well. Either it turns out to be a con or they get overrun by bears.