Maybe he means she'll incorporate some of her older sounds into the new album, or he means she will literally reference her past songs so she might say 'slave for you' in a song or 'hit me baby one more time' or something like that
I guess it has to do with some of the things she posts on instagram , like those butterflies pics... I guess this album might be kind of experimental or at least more personal if she really works on it (not like on Britney Jean) and has creative freedom
Y'all, he just means that when they are talking music, she will reference "things," meaning certain styles or particular songs, and those "things" influence the direction of her music. It was a statement that meant she has an active hand in creating her music and deciding the sound. This had nothing to do with her "referencing" any personal things going on.
I had hoped someone said it.
It'd been nice if he was specific but I guess we'll just have to wait and see.