If he gets snippy you could report him to eBay for incorrect contact information.
However, try to keep it cordial. Ask if he has a Forward Mail order at the Post Office. Ask him to go to his old address and ask the new tenant either to phone him when the parcel arrives, or to readdress it without opening it. The new guy doesn't even have to accept the parcel, just tell the postie to hold it at the PO for your buyer.
What you are trying to do is verrrry politely get him to recognize that the responsibility for his contact information is his, not yours.
That being said, as stated above, if there is a difference, ship to the Paypal address. But ask future buyers to confirm that the PP address is correct if there is a difference. It is easily changed.