Part of this feels like it's making fun of racism and the people who practice it, and the other part feels like straight up
.
But this was a 70s sitcom that was based in the 50s, so I was expecting nothing different than what I saw.
I kind of think this thread might be missing that.
Even though the 50's when the episode takes place was "only" less than 2 decades before the 70's, I get the impression that the world had changed A LOT more in those 2 decades than our current world has changed in the past 2 decades. The post-JFK/post-Vietnam world seems like a whole different century (at least on TV and in the movies). So the Happy Days scene is kind of saying "Look how far we've come in the past 20 years!".
Today if you watch a show made in 2004, the world has changed relatively little compared to then. (Other than that the Blackberries have been replaced by smartphones.)
Typing this out, I just realized something:
The title "Happy Days" is actually kind of similar to the whole concept of "M.A.G.A.". The "Happy Days" were the days when America was "Great". Before the JFK assassination, the Vietnam War, and the Civil Rights movement.
At the very least (unlike MAGA), the show had "some" awareness that the "Great Again" days weren't *really* that great for everyone all the time. They were sort of trying to walk the line between nostalgia, and acknowledging that progress really does exist.
I remember this shyt. 
