So they are no longer planning for through services beyond Aylesbury? That would seem incredibly short sighted.
The same is surely true for halving platform lengths from 212m to just 106m.
Is it short-sighted? Are people in Milton Keynes and High Wycombe desperate to travel between the two places? I have my doubts - and no one would be using it as a way to get between London and MK.
The only new station between Aylesbury and MK will be Winslow, where the main flow will pretty obviously be to and from MK, rather than west to Oxford or south to Aylesbury/beyond.
The Aylesbury service is intended principally to make commuting from Aylesbury to Milton Keynes easier. Opening up through journeys to places south of Aylesbury was never central to the business case, more a case of a potential operational convenience, though one requiring a fair degree of work on the Aylesbury-Princes Risborough route to deliver.
'Just' 106m means platforms will be able to take a four-car 23m train (or 26m if someone wanted), typically seating 240 or so passengers.
There will be 4tph on the section between Winslow and Bletchley shared by Oxford and Aylesbury services - 2 Oxford-MK, 1 Oxford-Bedford, and 1 Aylesbury-MK - which should be enough capacity to be going on with for a new regional route, serving an area where the absence of any rail service and poor east-west road links have acted as a deterrent to the development of strong commuter or leisure traffic flows anyway, so trains are unlikely to be full from day one.
We still don't know what longer-distance services may use the route either. There's no reason why an XC-type train of more than 100m in length could not run from further north, call at MK Central or Bedford Midland and then go on to Oxford from day one of the line opening, calling en route only at Bicester and Oxford Parkway, which both have long platforms, and share some of the traffic with the 'local' services.