>I can't see a problem, as long as the chips are not fraudulently resold.

In general, most components are only rated for 2 to 4 re-flow heating cycles before internal damage occurs. On some components the initial re-flow cycle brings the component into the rated tolerance, and for others the PCB forms a bimorph cantilever that physically fatigues the chip contacts/leads.

Production yields are only part of the Infant Mortality Phase of the bathtub curve.

Some components do get more stable with age if and only if left alone, but you can count those on one hand if you still have all your fingers. That is also a 3 hour pedantic conversation no one wants to have.

I am secretly a sentient turnip... =3