When Albus stopped by to give Oliver his gifts, Percy would've been there (hello, roommates) and would've said to him, "You realize everybody's been worried sick about you, but I'm not going to scold you for disappearing like you did, since I'm sure your mother and father already have. But I'm glad you're safe."
He would also thank Albus again, because he was the only one in the village who acknowledged his own birthday.