No, this is not the timing attack I was thinking of. Your version of timing attack comes from inside tor network and that is solved by Entry Guards. And besides you can also be Tor relay and a client. This attacks are just bugs that are fixed.

The real timing attack that is not fixed and will not be (it is not in threat model), is when your ISP works with police (that has warrant) and gives them data. And police also controls server or exit node.