Firstly, thank you for reading and commenting. You've raised some very interesting points here.

I absolutely agree that if someone is to decline to watch The Birth of a Nation that is entirely their choice, and I would respect that (though for me, I'd always rather see a film to have an informed opinion). I also agree that if an organisation (like TCM) declines to show a film, that isn't necessarily censorship either, provided the film is available elsewhere.

I do think Disney were being rather prudish over the nudity in the PG-rated Splash, but I don't know if that's simply down to the difference between American and British (or indeed European) sensibilities. It doesn't really bother us the same way. Nudity is acceptable at all levels of UK film classification by the way, even at U level (equivalent to G in the US) provided it isn't in a sexual context. At any rate, I have an uncut DVD of Splash (yet another reason why I always argue for physical media over streaming) but I'd say if someone has subscribed to a streaming service for a particular film or films, said platform should deliver them uncut, or at the very least with a disclaimer that they have been censored.

Your most interesting point is the idea that Song of the South should be thrown into the public domain. To my mind, it is an important cinematic artefact, and that might be the answer. I have no doubt that organisations like the BFI in the UK would certainly curate it carefully.