Surprise! Censorship

Readers,
       We recently turned in a paper on the topic of Adventures of Huckleberry Finn, so it's on my mind. On my previous two posts I commented on Adventures, covering both large scale and small scale attempts to censor it. However, I wrote both with the confidence that I had a completely uncensored text, that I was not missing any detail because someone else decided I couldn't handle the wording.

Recent evidence begs to differ.

As I was searching the book to find quotes for my paper, I came across a section called "A Note on the Text." This stated quite clearly that in our edition the phrase "the nigger woman's gown" had been changed to "Aunt Sally's gown," for no other reason except censorship, despite the fact that ownership of the dress is clearly implied.
        This might seem like a tiny change, not something to make a big deal out of, but I felt extremely short-changed. It made me think what else had been changed in previous editions, but no one had bother to write it down. It makes me glad that we have original copies of the text, to correct any major changes made to the text. This sort of experience makes me want to examine everything I have ever read to check if any of them had also been censored, because when I read an uncensored book I expect it to be uncensored. So what do you think readers? Is this a large deal like I think? Or have I simply blown it out of proportion?