The earlier proposal was to have one branch going through Dalston and the other to Hackney Central. The new idea is to branch further north and either go through Dalston or Hackney Central, not both.
My response to the consultation was a single line that stops at Haggerston and Hackney Central. This would save the cost of the two tunnels but would keep the costs and benefits of the interchange with both branches of the Overground.
However, I think Crossrail 2 is of very little benefit to South East Londoners, and we shouldn't pretend that one option is better for us than another, both are completely irrelevant to the major transport issues in South East London, even for users of the Overground. I'm still in favour of Crossrail 2 to relieve congestion at Victoria.
With the completion of Thameslink (North-South), Crossrail 1 (East-West), Crossrail 2 (SW-NE), and HS2 for the NW, the only part of London that requires a major new tunnel is the SE - possibly the Bakerloo line extension - the cheapest of the lot by far.