I understand the point, and I think it is good to correct people when they refer to Ukraine incorrectly.
However, comparing a (typically accidental) prepended word to slavery makes me recoil from your argument. I think it is similar to "Reductio ad Hitlerum"[1]. People who refer to the current country as "The Ukraine" are incorrect, but saying that they are implicitly supporting the history of that name is overreaching.
I don't think most westerners even associate anything particularly problematic with a prepended "the". It's used in "the Netherlands" for similar historical reasons; like the Ukraine, the Netherlands was a descriptive term for a certain region before it was a sovereign state (the Ukraine meaning the borderlands, and the Netherlands meaning the low countries). Whether it's retained or not when the region became a sovereign state seems more or less arbitrary.
However, comparing a (typically accidental) prepended word to slavery makes me recoil from your argument. I think it is similar to "Reductio ad Hitlerum"[1]. People who refer to the current country as "The Ukraine" are incorrect, but saying that they are implicitly supporting the history of that name is overreaching.
[1] http://en.wikipedia.org/wiki/Reductio_ad_Hitlerum