12 Year old suspended from middle school for.....

My 12 year old son was suspended for lying about the location of his agenda book. He states it was a misunderstanding but either way he received 2 days outdoor suspension from his middle school. He is ADHD and working with his therapist about taking responsibility and lying. I was told he wont miss anything but the social aspect because grades are closed. What does suspending him do? I requested that he have a less severe punishment but it was denied. Does this sound harsh? I'm so frustrated. Thanks for letting me vent!