I don't know. I think the same objections about plausibility and probability apply. Of all the upper-class households in London, Oliver Twist just happens to break into the house of his long-lost great-uncle? Quasimodo and Esmerelda are switched at birth, yet just happen to cross paths later on in the most dramatic of ways, completely unaware of the secret connection between them? Unlikely connections and coincidences are the stuff of classic myth and melodrama, and seem to be what people are objecting to when they complain about "small universe syndrome."
Speaking of which, there was a BBC miniseries from a few years ago called Dickensinian that made an effort to connect all of the Dickens characters and stories together.