Janet Jackson Mum on Justin Timberlake Reunion, But Back with Jenna Dewan

Janet Jackson threw the hottest high school reunion Sunday night at the Hollywood Bowl, bringing back a ton of her OG backup dancers -- but she's not letting on if a Justin Timberlake reunion is in the cards.

We got Janet outside Lure Nightclub in Hollywood, where she held the after-party ... and asked if she and JT might reunite at Super Bowl LII. According to multiple reports, Justin's locked in for the halftime show -- so, you gotta wonder if they'll patch things up after 2004's infamous boob debacle.

If it's happening ... Janet can definitely keep a secret.

As for her backup dancers -- Miss Jackson gave them all some shine during the Bowl concert ... including Jenna Dewan Tatum, who originally debuted on Janet's 2001 "All for You" Tour.

They are a part of the Rhythm Nation ...