Ashanti talks about the Queen Jennifer Lopez at 5:00 And its normal for a song to have background singers! As Ashanti said her vocals was mixed with Jen’s voice to add flavor or style to the song. And she said it is normal in the music industry. Its not the first song that a chorus was mixed or sing with the background singers. Some examples:

Alicia Keys – You Don’t Know My Name John Legend,
Diana Ross – Chain Reaction Brothers Gibb
Madonna – Justify My Love Lenny Kravitz
Whitney Houston – Step by Step Annie Lennox
Carly Simon – You’re So Vain Mick Jagger
Selena Gomez – Same Old Love Charli XCX
Rihanna – Disturbia Chris Brown
Rihanna - Diamonds (Sia)
Toni Braxton - He Wasn’t Man Enough

Not sure why people are shocked like it’s a new thing. Most girls out here doing the same Shh1t people just love to drag her because your fave could never be relevant as jennifer even when she is 50 years old she has in just one year a succesfull tour + successsful movie + awards (20 movie awards as best female on Hustlers + 2 icons awards on Billboard and People) + superbowl + new years eve + inaguration.