The halftime show press conference has been a tradition for YEARS -- Justin Timberlake held one last year, Gaga before that ... Prince famously busted out his guitar and rocked out at his back in 2007.

So, why scrap the presser? The NFL says Maroon 5 and the other artists like Travis Scott want to "let their show do the talking" -- but it seems pretty obvious it's all about Kaepernick.

There's been a strong push from big stars like Common and Nick Cannon for the halftime show performers to pull out over the way the league has treated Kap.

Other stars like Jay-Z, Rihanna and Kelly Rowland have said they wouldn't work with the NFL in the wake of Kaepernick's allegations he's been blackballed for taking a knee during the national anthem.

SportsBusiness Journal's Daniel Kaplan says the presser had been on the official schedule of events -- and NFL Network's Ian Rapoport essentially confirmed by saying the presser was "canceled."

The NFL issued a statement saying ... "Maroon 5 has been working hard on a Pepsi Super Bowl LIII Halftime Show that will meet and exceed the standards of this event."

"As it is about music, the artists will let their show do the talking as they prepare to take the stage this Sunday."

Instead of hosting a press conference, the NFL says the artists and the league will participate in a "social and digital media rollout" to promote the show.