You simply can't tell. 73% loadfactor isn't especially high for a long-haul service and there is every prospect that the yield isn't high as Cardiff has been included in every Qatar Airways low fare promotion going. You can easily fly services at 100% loadfactor and still lose money. What you can tell is that the service is not doing well from a cargo perspective. 8 tonnes uplifted from the entire airport in the month of August is dire. Given that cargo accounts for a good proportion of long-haul income, the absence of it certainly won't be helping the economics of the QR service but whether they're good, bad or indifferent to begin with would be pure guesswork.
Far far too early to be hanging out the bunting yet.