Unless there were weather fears I imagine it’s due to accommodating the wishes of the various international broadcasters and to increase worldwide audience figures.
Basically it all down to British Summer Time meaning the UK is running an hour ahead of the rest of western Europe. Means the timetable starts an hour later than usual but need to keep the main MotoGP race in the same time slot for TV broadcasters elsewhere in the world.
Personally, I prefer that running order as the Moto2 race is often a snoozefest and I need to liven myself up ready for the MotoGP race.
Have to say I agree with @gomezz it's a far better running order.
It also means that the Moto GP riders can't complain about changing track conditions from morning warm-up to the race due to extra rubber being laid down by the Moto 2's.