Maybe he starved it of oil, maybe he took an extended high g turn and starved it, maybe he put the wrong oil in it, maybe he didn't change the oil for 30k miles, maybe there some ball detent in the head that wore down and lost oil pressure and is a new issue that needs to be monitored.

There's a ton of possibilities, granted most of us change our oil on time with the right type and right amount so its not an issue, but its worth mentioning.

 

If it has internal damage like knock, you should have the engine cooler and lines replaced as well when replacing the engine. You don't want metal shavings / particles going into your new / used engine.

 

If I remember what I read correctly, the engine oil cooler is directly after its filtered, so theoretically you wouldn't need to do this, but Its not a bad idea either way. Id replace them on the side of caution. Or change the oil on first startup and at 100 miles if you’re really worried about it.