The A380 didn't have an STC and it wasn't worthwhile for QR to invest time and money on one for only 8 aircraft which are planned to be withdrawn starting 2028. Starlink has more demand than it can handle so for them it also wasn't a priority either. QR went with a different solution for the A380 that was already certified.
Things changed now that EK has committed to install Starlink on their fleet, they will develop the A380 STC. It will be question of if QR decide its worth it with only a couple more years of service left, the constraint is how fast Starlink delivers the kits with the huge backlog they have and QR might prioritise other aircraft in their fleet.