As long as the sausage has been frozen the sausage is okay to eat after expiration date.
Sausage can be kept in the refrigerator for 2 days before it goes bad but you can keep sausage in the freezer for 6 months to a year past the expiration date.
The expiration date just means that the sausage is not as fresh as before once the sausage gets past the expiration date but the sausage is still good to eat after the expiration date as long as it's remained frozen.
If you plan to keep the sausage longer than 3 days you should freeze the sausage until you're ready to eat the sausage.
Expiration or use by dates on sausage or other foods is just a general guideline as to the freshness but it doesn't mean it's bad past the expiration date.