>>1678981not sure if i'm missing something, but, Birmingham is definitely going to be reachable from further North via HS2. trains aren't just going directly to London from where they set off. for example, there's a big flying junction going to be constructed just south of where it forks into the western and eastern legs.
so, trains come from Euston, call at Birmingham, then head onward to either the Manchester leg, or to the Leeds leg. likewise, trains coming south from Leeds can call at Birmingham, then head north to Manchester, and vice versa.
they won't start making firm timetables and service plans until they're ready to lay track and OLE, anyway, and of course that's going to be the very last thing they put down.