Will be interesting to see the official findings on why such a new , low hours engine failed so spectacularly.
JACDEC has the aircraft as being 2y10m old. That would give the engine in the region of 15,000 hours of operation (assuming it is the original and about 5500 hours/year).
I know that BA now with much experience) get over 20,000 hours on wing from most of their B747 RB211-524G engined fleet.
So if it is the original fit, it is not a 'new' engine and may have been approaching overhaul, given that the Trent 900 is a recent development.