The only thing I've heard Chomsky say about it is that it's silly to name it marxism, basically. He points out that Freudianism is the only other personality cult like that in the sciences, and is total bullshit.

His point is that marx should just be considered one of the thinkers of sociology like any other, and that by fetishzing the one person, marxists fall prey to not tossing out the ideas which will inevitably become obsolete as science progresses.

He did give credit to a bunch of marx's theorizing about capitalism, for sure. But I think he is wary that calling the thing Marxism would lead leftists to tend to stan/uphold cults of personalities around various marxists which... he isn't completely wrong about any of that, tbf hahahaha

I can't find anything of his on 'dialectics' in particular, just on marxism broadly