The timings haven't changed since they were booked for Turbos and it does make sense to time them for Turbos as they are substituted for one fairly frequently.
But rather less frequently in the past couple of weeks. And there's precious little point retiming them, as pretty much the entire Cotswold Line timetable is constrained by the need to fit in with the Oxford-London regular interval timetable and the remaining sections of single line anyway.