I'd be curious to know
how this was perceived in 1941, especially by black people. It's dreadful by today's standards, not funny, and personally I don't particularly like the song (which you could argue is what the cartoon was about and there seem to be several covers of it on YouTube).
But it's imagery seems much the same as other cartoons, and real life films, of the time so it's just another example of things we now look at differently.