No actually it is LAW, if the returning gun has a different serial number, which I'm guessing it will. Your gun will most likely be scrapped, and that serial number will be noted as scrapped. The new gun will be sent to your FFl free of charge and will then need to be 'transferred' to you ... which will cost anywhere from $20-50 for the FFL to do the paperwork.
Get a receipt for the transfer, and send it (or a copy) to Ruger and they'll send you a check reimbursing the transfer fee to you, which is EXACTLY as it should happen.
Congratulations !
REV