Er, he suggested that *all* sabbs start later, not just the DPGS.
Changing handover dates at all are a daft idea if you ask me. Previous sabbs that were masters students managed to take an interruption of studies during their masters in order to start their sabb post. Why should planning for the new academic year go out of the window because a small number of sabbs lack the wherewithal to get off their bums and sort such an arrangement out for themselves?
Plus such an arrangement could have a severe impact on non-masters sabb officers (I'm thinking in particular of the medics sabb here, with their weird term dates, academic years starting at the start of July etc etc).
It's not just a question of 'wherewithall'. It's a lot easier to defer a desk-based project in college, than a lab-based one with an external research team, or a field-based one that would be invalidated if half the results were from a different season, so there's a big difference in what you would be asking for students in different subject areas. Make deferring compulsory for the post, and you'll end up with a "DP Tanaka".
Changing all handover dates does seem like a sledgehammer to crack a nut, but with the DPGS post SPECIFICALLY for postgrads, that at least should be accessible to a good cross-section of them.
In reply to point of information, I don't know when the last time a Masters student deferred their project for a year to be a sabb was, but hasn't a PhD student just deferred his project for a year to be a Sabb?