A theme that Donald likes to explore is creating surrealism out of the banal, apathetic and cynical aspects of life. Another theme of Glovers work and attitude is reframing the experiences and art of Black Americans as something to be celebrated and romantic about instead of hyper focusing on the bad. Glover has said that Migos were "The Beatles of this generation" and that Tay-k was akin to Wild West outlaw Jesse James and I dont think he was joking or being hyperbolic, he sincerely believes that.
I see this American Dream project as inspired by these themes. It will have some autobiographical influence but mostly be a tongue in cheek satire of bio pics focusing on the complex journey of 21 but ironically with the understanding that 21 has no explicit substance to him or his art.