Oh, I understand your perception of the term, but it's not commonly understood to have that meaning.
Among blacks, an 'Uncle Tom' is a black person who isn't 'down for the struggle' against the majority culture/population/traditions, or you're someone who considers themselves to be part of the mainstream.
In other words, if you're not a honky hating, class warfare raging, black power advocating Marxist, then you're a 'sell out' to the 'cause'. You're a disgraceful, self-loathing black person, who doesn't deserve the skin you were born in.
That'd be me.
No worries. At times we debate with the language of the left. Just like when we talk about classes, straight out of Marx.