any IRS and state notices would be sent to the latest address on file which should be what's on the current return. They would have no way of knowing that you didn't move. if a refund check had to be mailed to you it would go to 12345 and since you don't live there the USPS would return it to the IRS. Reasons enough to correct. It certainly can't hurt. Call the state's income tax bureau to find out how to correct the address in their records.
