In an interview with The Guardian, Madonna famed producer Mirwais, explains why Madame X reunited them

[Spicechinodiva]

Mirwais Well associated with His work for Madonna, Particularly 2000's Music, 2003's American Life and beginning stages of Confessions on a dance floor before Madonna changed the direction as he was making the music political and Madonna felt her documentary 2005's I'm going to Tell you a secret was her political statements, the Music needed to be something. 

 

So he virtually disappeared after the initial stages of the project until they reunited for 2019's Madame X. 

 

Basically why it happened. Simply.

 

"All these American Celebs from Miley Cyrus, Rosie, Whoopi threatened to leave the US if Trump was elected but never did. However, Madonna stayed true to her word once he won the election she moved her entire family to Portugal.. the other celebs was empty words, But Madonna stayed true to her word and that should be admired"

 

He also said Madonna is a bull in the studio, she has a direct vision you find yourself literally bullfighting with her to have an artistic input,  but overall she says it best, it's not a collaboration, it's a Madonna album and you're the producer, but I'm the executive producer and A&R, meaning I have final say it what gets out.