QR already had plans for this 2 years ago. They were pushing Airbus hard on it. Airbus has already agreed to it and a company in Singapore is ready to do the p2f conversion
A330P2F passenger-to-freighter conversion | Airbus, a leading aircraft manufacturer
As the 787 and a350 come online in large numbers the a 330 will become obsolete, with the huge numbers in service this is the best way for both operators and airbus to cash in.