The parts were sold to jet engine maintenance organizations, not to the manufacturers.
After some number of hours of operation, airliners are sent to repair shops, often in developing countries, for routine teardown and replacement of worn parts.
>>More than 900 aircraft maintenance and repair stations have been certified by the Federal Aviation Administration (FAA) outside of the United States. The number of these facilities has grown by more than 30% in the past four years. These foreign repair stations are located all around the globe including China (78 facilities), Singapore (54), Brazil (22), Thailand (6), Costa Rica (3), and El Salvador (2).
https://www.twu.org/current-issues/foreign-aircraft-maintenance/
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