In the interview where the artist discusses his life and his artistic process, he is also asked about projects he has in the works for 2017. His reply is the following:
I made a remix for an artist named VOIA from the Attack the Music label. He is based in New York and has a great talent. I also made a tune for the game series Persona 5. I am currently working on new M-Flo tune.
In the original Japanese text, he states that he specifically “remixed” music from Persona 5, which he says “may be included in the next game.”
Nothing more has been stated regarding this, however it seems like a definitive statement that DJ Taku Takahashi has worked on the music for a future Persona 5 project.
In the Atlus Japanese 2017 consumer survey, one of the questions listed a “‘Persona 5’ dance game (sound action)” as a proposed title fans could show their interest for. Persona 4: Dancing All Night was a game which employed various Japanese guest music artists such as Metal Gear Solid composer Norihiko Hibino.
This mention by Taku Takahashi could hint at a similar project for Persona 5, but it could always be something completely unrelated.