Yes, that's how I interpreted it. If you don't tell them you are subject to sanctions. If you do tell them they will take your ticket back without a refund and resell it. Sounds borderline illegal to me.
What good intentions? I don't see any.
If you can't go you must give us your ticket for free or you will be subject to sanctions. Then we will sell the ticket again. This is appalling and bordering on illegal.