In Agile, you are supposed to ship product on a regular cadence. All features are added to a product backlog, divided into small projects that fit within a sprint, and then prioritized. The backlog is just a way to keep track of all of the ideas people have, requests from customers, major bugs and other things.
The first patent for Pristiq is set to expire in February 2022. This is the earliest predictable date that a generic version of the drug could become available. However, other circumstances could come up to extend or shorten the exclusivity period.
Researching expiration dates and terminal disclaimers in a patent family that takes two patent pages to explain is too large a task for idle curiosity. So, the idle curiosity answer is that the important SawStop patents probably expire somewhere around 2021, give or take two or three years. Remember, it would be foolish to use this information for anything other than satisfying idle curiosity or impressing friends at the TechShop.