I suspect "Crewe Hub" will consist of some 400m long classic compatible platforms allowing trains to split/join en route to Liverpool, Preston and Chester.
No sense in stopping Manchester services or installing European gauge platforms at Crewe. 2-3tph will be quite sufficient to serve Crewe.
This is what I think will happen. By having 400m CC platforms at Crewe, it will mean trains can join/detach there before joining the HS2 route which will rationalisation of Crewe-Birmingham paths. If 200m CCs have to run to Birmingham before they join that will surely be deemed a huge waste of capacity down the line. Whether Crewe gets these platforms now or at some point down the line, it is inevitable.
By the time HS2 opens, I could see wires going up to Chester/North Wales and we will have the completion to Blackpool. with 400m platforms at Crewe, That would mean an Hourly Chester/N-Wales train and the hourly Preston (Blackpool) train could each join a Liverpool train at Crewe and use no more paths than current proposals. (It may infact save one). If Liverpool did then get a direct captive connection, these could then join each other thus still keeping the same total number of paths as now.