She will be Andre Holland's daughter who shows up in Paris and "forces him to face his past".
The OP ctrl+F 'jazz' on the article and got 0 hits. So maybe Mr. Chazelle is branching out in his musical tastes. But the segment "[....] set in contemporary multicultural Paris revolving around a club, its owner, the house band, and the chaotic city that surrounds them." suggests otherwise.
At least he knows about black people now.
The Eddy is set to premiere on Netflix in 2020.
thankfully she won't have to say 'negar music' in this project. probably.