Do they still have 767?
As far I know,
Asiana decided to fade out 767 sonner or later. 767 fleet will be changed by A330 or 777.
They also have plan to fade our 737 fleet which will be substitude by A321.
I'm not sure about roster but I'm sure they will never give you a chance to transfer 777 or A330 within decade which will be lot longer than thier plan for 767 fade out.
but who know's~
Asiana always change thier plan in one second with easy finger snap.
Eventhough it makes us confused, who care~
Good luck.