It’s unknown whether and to what extent fans will attend games in 2020. Per a source with knowledge of the ongoing talks between the NFL and the NFL Players Association, the league wants to give teams the ability to hold up to two fan events at their stadiums, during training camp.
The union is willing to do it, with limitations.
The number of fans would be restricted (and subject to agreement), and they would be kept distant from players. There would be no interaction between fans and players, and fans in stadiums would be seated a specific number of rows from the field.
Fans also would be subject to temperature checks and screening for symptoms. In domed stadiums, the team would be required to address air-exchange issues before fan events proceed.
The union’s willingness to consent to this approach depends on the number of preseason games to be played. Given that the players want no preseason games, it’s likely that the players will want no fan events during practice, or perhaps only one.