Actually, it is more the case that the specific serial# engines installed in those aircraft are ones that have already been run the prerequisite hours to be properly "rubed-in".
It is not the aircraft but the engine - the one that failed was nearly new - ones with higher hours have already "worn-in" sufficiently to be safe to fly in all regimes.
The flight restrictions are for the "rub-in" period only - I suspect that they might just start running them a lot more hours at P&W before they are shipped to be installed in aircraft.