Good question, especially with everything going on around DXB.
If Emirates cancels the flight, you won’t need to use their refund form since it was booked with QFF points. Qantas controls the ticket. Normally when a partner reward gets cancelled, Qantas will either:
Rebook you on another Emirates flight if there’s availability in the same cabin
Offer an alternative routing if possible
Refund your points and taxes back to your account
You don’t just “lose” the seat, but you’re also not guaranteed another Business seat if there’s nothing available. Reward inventory is still reward inventory.
If it were me, I’d call Qantas Frequent Flyer rather than wait, especially if DXB is still shaky close to departure. Partner bookings can get messy last minute.