Not at all. Pivotal figures in civil rights, such as Du Bois [1] were anti-capitalist and much of contemporary social and legal theory emerged in the 1980s from post-modernism, a direct offshoot of Marxism. The general idea being that if you switch out “class struggle” for “racial struggle” then you get to borrow the rest of Marx’s theory about an oppressed proletariat and the need for revolution to overthrow an oppressive elite.
Americans like to use “marxist” as a slur and to use it out of context to attack political enemies but there is no shortage of actual Marxist who label themselves as such, e.g this professor, found randomly by my Googling for 30sec: https://blog.apaonline.org/2020/06/17/black-lives-matter-as-...
Most people have no idea that they’re regurgitating Marxist ideology when they repeat the phrases and arguments they hear, and of course would never identify as such - but there’s no sense in which making this observation is misinformation.
Personally I lament the fact that people across the political spectrum are digging ideological holes for themselves instead of focusing on how we can all help each other.