At Phase 2A everything going north will have to leave HS2 just south of Crewe and proceed through the station, stopping or not. Expect small alterations to accommodate this and retention of the fast lines through the station. In Phase 2B the tunnel is constructed and once the new routes are complete towards Scotland and Manchester, fast trains to these destinations will begin using HS2 under the station, allowing a more comprehensive modification to take place. The existing junctions will all have to be renewed in the next decade or so anyway, so this offers a way to do it economically and incorporate any changes at the same time. Removing the fast lines on the surface and rearrangement of the north end together with some additional platforms to allow Manchester - Shropshire trains to use the independent underpass could allow a simpler and more effective and reliable layout to be built, with more capacity and fewer conflicts. The recently announced north junction will allow HS2 trains from the south to pull off and call at Crewe then rejoin the high speed line for Manchester or Scotland. It's plausible Manchester/Scotland - Birmingham trains might do this but unlilkely many London trains will. Liverpool trains will continue to pull off at Crewe and run via Runcorn for the forseeable future until a coherent plan emerges and an additional dedicated access line is built into that city, likely shared with NPR services and routed via, or near, Warrington. I've personally had my doubts over the value of the latter, but at least, even though longer than the Runcorn route, it should be able to compensate on journey time by its speed for at least part of the way, and importantly it would avoid (at least some) HS trains running on the busy double track section between Crewe and Weaver Jn, track which, although very straight and direct, is shared with freights and local stopping passenger trains, which limits practical speed and scheduling freedom as well as importing operational risk. If new dedicated access to Liverpool is built, then it's likely at least some Liverpool trains will bypass Crewe via the tunnel although I suspect at least one an hour may continue to run via Crewe to retain a service from that important interchange hub. With its long platforms, Crewe could provide the opportunity for such a Liverpool train to combine with (say) a Preston/Blackpool 'stopping' portion south of there to save paths on the trunk.