The person in this scenario could still choose to go to jail instead of rehab. They could also slack off in rehab and start using again once they are released if they so chose. Obviously these are not ideal solutions but the person still has some kind of choice in the matter. Hopefully they would take it seriously and choose not to go back to drugs.

“Re-education” would be if they were sent to some kind of Clockwork Orange style reprogramming process where these choices were taken away from them, making them unable to ever do drugs again wether they wanted to or not.