Uppity in isolation is not necessarily racist, unless it's being used in combination with another term which most definitely is racist, and I'm hoping that this post won't be removed as I'm merely using the following link to illustrate a point:
https://www.urbandictionary.com/define.php?term=uppity%20nigger
Read Roots, or Uncle Tom's Cabin.
I can't even begin to imagine that that's how it was meant in this context, merely an example of how it could be misconstrued as pejorative.