Those cartoons are blatently racist in that they portray the black person as unintelligent, uncultured savages with cannabilistic tendencies. The Coal Black and the Seben Dwarves is different to the whole black=savage concept of the others (I admit I have only watched three in completion) in that it twists a typical white story into one with very stereotypical black characters. I don't feel that that is very appropriate child viewing since all it does is teach the bad habit of extreme prejudice.
I don't believe that any of them should be shown on the same level as other, uncontroversial cartoons but it would be wrong to cast them into the pit of oblivion that is the wiping of the tapes, just as it would be wrong to remove Mein Kampf from existence. They should not be viewed in the way that they were intended but I think it would be a shame (and wrong) for part of history to be simply erased because people don't like what they were not that long ago. I think that the situation that exists now, with the cartoons being in the public domain as examples of the racist or at least heavily prejudiced media that have gone before but they should not be shown mid-afternoon on a saturday for kids to watch and inevitably learn from even on a subconcious level.
If these clips were say, banned Monty Python episodes (I don't know if any exist,) or something that is basically aimed at already educated people and contains material that some may find offensive if they view it in the wrong way, or something more current such as the banned Family Guy cartoon, 'Wish Upon a Weinstien' (i think that is what it was called. It is available in a poor quality rip on many p2p networks, although the legailty of that is pretty grey, the makers are only going to want to stop people through shame of what they created as opposed to any copywrite theft or loss of business that would occur) then I would feel that something I could appreciate as being funny yet at the same time poking fun at or using stereotypes of a specific race or religion had been taken away from me unfairly.
edit: wasn't aware the Family Guy eposide wasn't actually banned. Damn. Well, if you pretend it is then my argument still kind of makes sense-ish.