Herbert Gans's book "Levittown" talks a lot about what new suburbanites did to relieve their loneliness & isolation. They created all sorts of clubs - book clubs, sports clubs, cocktail parties - but none of it, from my reading, seemed to have been much of a substitute for Bubbe and Zahde around the corner to help out with the grandkids.
Ironic, isn't it, that "empty nesters" and gays spend fortunes on rehabbed and gentrified townhomes in the very neighborhoods that fifty years ago held large, vibrant family-oriented communities?
I am impressed with your knowledge of the era of Patti Paige and Arthur Godfrey.
I wonder whether the consequences were unintentional or sought. A theme of the time ("Peyton Place", for example) was the stiffling conformism of small town life, of a world where reputations were set in concrete, and the hypocrisy it bred. The tyranny of Miss Grundy. Moving to the new suburbs, away from the relatives, to a place where nobody knew you, was shaking off the old patterns, reinventing yourself. There was freedom in that and a new privacy where nobody lived above or below or near enough to hear your conversations. You could choose precisely how much contact you wanted with your neighbors. You were physically moving yourself to a place where "what the neighbors will say" no longer is of any importance because they are mostly strangers to you. In an extended family, a divorce would be a civil war. In a nuclear family there is a limited societal ripple effect.
The move to the nuclear family, to get the inlaws and cousins and grandparents out of your hair and out of your business was chosen. It was just one step further to the age of individual autonomy in the 60's and 70's.
An interesting point you made about gays and empty nesters gentrifying urban America. Crime has made cities child hostile and good urban public schools are few and far between. A point that Jane Jacobs made is that bohemians look for cheap places to live, but because they have excellent taste and are fun to be around, the area they choose swiftly appreciates in value.