I remember seeing this on a "Best of Laugh-In" retrospective in the mid-'90s, and it blew me away then.
I remember that when they aired them on Nick-at-Night in the late ‘80s (Laugh-In was cancelled in ‘73, a year before I was born). Not only got the year right of the Berlin Wall falling (except for the moat part) and Reagan being President 20 years later, but I rather wish Reagan had come back to run for Governor after he was President and stopped that RINO bozo Pete Wilson. ;-)
That segment is my favorite Laugh-In reel just because of that.
Damn! He nailed the falling of the Berlin Wall and RR in the WH to the YEAR!