It looks like the world supply of spare Trent 900 engines is now used up; SQ is changing 1, LH 1, and QF has found 3 more bad engines. The new inspections are turning up signs of oil leaks (the Trent 1000 uncontained engine failure during takeoff power static test for 787s was due to an oil fire which weakened the shaft, causing overspeed and eventual turbine disc destruction -- somewhat similar to the known Trent 900 symptoms and now inspection is finding potential predecessor conditions).