Is there some historically noteworthy event associated with the lake in question?
I am certainly not suggesting that "Adventures of Huckleberry Finn" be rewritten or edited to remove offensive language. To do so would remove some of our history. That novel is a product of its time and the time that it depicts. I am not upset about (but admittedly have not read) "Go Set a Watchman". From what I have heard about the novel, it describes how Atticus Finch is a product of his time. I can understand how people are disappointed with the character (and have transferred that disappointment to the author)--I think they attributed something to this character in "To Kill a Mockingbird" that isn't actually there. I wouldn't suggest that either novel be rewritten or edited.
If I am correct that the name of this lake was changed in 1962 by the U.S. Board on Geographic Names because it was offensive, if people are now offended by the "improved" name, I see no reason not to change it again.