That episode did not particularly evoke a response.
Its setting was a single episode of an absurd slapstick show about an alien who misunderstands earth customs and his marriage of a pair of 11 year olds (who refuse to kiss) does not serve to frame a discussion on the topic of race.
To compare, about 4 years earlier were the Willises, an interracial couple on The Jeffersons, which was much more of a TV milestone.