Because when you're testing you put your rocket in an orbit that makes it reenter, but you can still show it has the performance to do it. They still need to s

Because when you're testing you put your rocket in an orbit that makes it reenter, but you can still show it has the performance to do it. They still need to show they can reliably relight the engines to deorbit. They're actually very good citizens there. Prove you can deorbit before putting anything in orbit