I think the nostalgia is also in the 2nd tv series as well. The Addams Family was the original series from the 60s.
It’s very common for reactionaries to seek to rewind the clock to a “better” time because the present has all these modernization problems. For the boomers, the 60s were better than today. For Gen X, maybe the 80s were better.
Both the 2nd and 3rd tv series are aimed at younger viewers or the young-at-heart: trying to convey the joy of youth.
I think for boomer liberals, their memory is pretty hazy and the 60s was the end of racism. “We did it guys! Everyone can sit on the same bus seats.”