Although the current CBA does expire until the end of the 2020 season, it is thought to be the most contentious and complex negotiations to date. The NFLPA is thought to have a huge and complex laundry list of demands they want addressed and resolved in th e new deal. Because of the complexity the NFL has wanted to get a leg up on the timing and possibly have an agreement in place by as early as this coming SB. Not so much now due to 2018 ratings. They are now willing to let this drag for years to come.