DD (14 / yr 10) & I have been discussing this in a rather non-conclusive sort of way.
Her English teacher recently expressed the view that they should be 'moving on to adult books and the classics' (context was none of the class recognising the Magwitch scene from the early part of Great Expectations when it came up as an extract in an English exercise) - mentioning Austen and Dickens specifically.
I wondered what books others thought teenagers 'should' read - I'd say Austen for sure (though haven't suggested them to dd before because my feeling is she's only just getting old enough to appreciate them). But there's an awful lot of writers I'd suggest ahead of Charles Dickens - should you read him just because he's a 'classic'. (And why Dickens over say Mrs Gaskell or Trollope's political novels or Vanity Fair?)