Modern rural living in the developed world is not much like rural living in most of history, so, no the modern rural living the GP criticized was not the “default norm” for most of history.

> The aberration here is not people with limited contact to others. The aberration is that in recent decades it is the new norm to work at a job that exposes you to many people every day and attend a public school that exposes you to many people every day.

From the various descriptions of historical rural life (e.g., medieval European village life) I've seen, neither adults nor children having daily contact with numbers of other people rather than being isolated with their nuclear family was at all uncommon; for most of history that wouldn't be school for children or wage labor for adults, but it would still happen.