I suspect you could probably draw a line between those posts complaining that what's being marketed as 1990s nostalgia is really just mislabelled 1980s nostalgia, and those posts remarking that it's become okay to make fun of the 1950s now because the principal object of reactionary nostalgia is no longer an alternate 1950s with no civil rights movement, but an alternate 1980s with no AIDS crisis.
I think it’s more that the “lost golden age” has been updated from The 50s to The 90s.