No. There is a redeposit fee for your miles to go back to your account (at least for general members): "When requesting a reinstatement, there will be a $150 processing charge per account for the first award. Any additional awards reinstated to the same account at the same time will have a $25 USD per award."

However, if you make long range plans and there are schedule changes, you may be able to cancel the award and get the miles back for free instead of accepting changes. (I did this once when they made a connection way too tight for my elderly parents travelling alone.)