The rumblings on Twitter and the blogosphere indicate that the 17th regular season game is coming in 2021, though nothing is official yet. The NFL did, however, decide on the framework for a possible 17th game in negotiations between owners and the player’s union prior to the ‘20 regular season.
Peter King wrote about that yesterday. A lot of information from his article is the basis for most of what you’ll read here.
Scheduling formula
Here’s what was decided at that time: the added game will be an inter-conference matchup, and will not be played at a neutral site, but will create an imbalance in home & away games.