Yeah, based on his track record, I don't know exactly what to feel about this one. Moh does look good as Bruce Lee and Margot Robbie is a good choice for Sharon Tate, but I'm not entirely sure how a black crime comedy film about the Manson murders will play.
They could play it like Inglorious Basterds and have Bruce Lee save Sharon Tate at the end.
"...you'll still be here trying to act cool while actually being a bored and frustrated office worker with a vibrating anger-valve puffing out internet hostility." - Falconeer "That looks like English but I have no idea what you just said." - Trippy
From what I am reading (and the internet is never wrong, right?) the movie is not specifically about the Tate Murders. They just happen at the same time and place as the movie is set and will probably be story adjacent but not central. But ultimately who the fuck knows.
Also as Rishathra said I wouldn't be surprised if he changes what actually happened.