This is an interesting situation that's kicked off on twitter via an article written by 2 female theatre writers who were commissioned initially to work on developing and idea with Idris Elba - see here for the initial statement https://medium.com/@toriandsarahburnbright/tree-a-story-of-gender-and-power-in-theatre-23b8a2468224
The resultant show, Tree, is just beginning at the Manchester International Festival, and is discussed in a joint interview with Idris Elba and Kwame Kwei-Armah in the guardian here https://www.theguardian.com/stage/2019/jun/24/idris-elba-kwame-kwei-armah-tree-interview-bereavement
This tweet highlights a couple of points that illustrate how the 2 female writers have been erased from the narrative completely https://twitter.com/hinge_xanderl/status/1145996282747662336?s=21
Kwame Kwei-Armah has responded with his own statement https://twitter.com/kwamekweiarmah/status/1146060767898165249?s=21
And the Green Door Pictures, Young Vic & MIF have issued a joint statement here https://youngviclondon.wordpress.com/2019/07/02/a-statement-on-behalf-of-green-door-pictures-manchester-international-festival-mif-and-the-young-vic/
It's a fascinating and revealing story on how female writers were erased completely from the creative process, and neither Idris Elba nor Kwame Kwei-Armagh come out of this well. But the support the women are getting for their own initiative BurnBright is great. More power to them.