That's really interesting - I'm a bit surprised they show it on TV anywhere, especially on the Disney Channel (though I knew about the international home video releases). In the US it's a whole different story - it hasn't been shown theatrically in 30 years, and it has never been out on video in it's entirety.
As much as I don't think there should be a problem with releasing it for historical purposes, it would be such a crapshow in the US - particularly in this "click to protest" Internet age. People that don't even know what it is, or have any idea what it's actually about, or any historical perspective, won't care - they'd see "Disney Racist!" headline and "click click click/send".
At this point, we are lucky that they haven't gotten rid of "Gone With The Wind" and "My Fair Lady", too.
But where this is Disney, it wouldn't matter what disclaimers, warnings, etc. they used - just making it available would make enough people complain (still relatively a small amount, but loud trumps numerous) that it would be a PR nightmare for Disney. Even folks like me, who understand how to put it in it's historical place, would be in the minority of the minority because most people just wouldn't want to touch the topic with a ten-foot-pole, even if they agree with it being available, for fear of being labeled racist.
In the end, it's just not the greatest film to begin with, which also hurts the case against it (which is something GWTW and MFL at least have going for them).