This came up on the other forum. I've not read it, though I read a fair deal about it. My thoughts are more general.
The notion of "cultural appropriation" is pernicious, balkanizing, and spits in the face of one of the founding concepts of our nation, one essential for a nation predicated on a creed rather than ethnicity, that of the 'melting pot'.
And I guess I'll regurgitate my take I have on it from the other board:
Regarding American Dirt, Mexican American novelist and poet Sandra Cisneros (The House on Mango Street) called it "the great novel of Las Americas".
Additionally, Dominican American novelist/poet Julia Alvarez (In the Time of the Butterflies) declared it a "dazzling accomplishment".
The most ridiculous notion underpinning this whole controversy is the idea that the experience of immigrants, Mexicans, or Mexican immigrants is monolithic; and, that therefore, the author can be called out for "inaccuracies". Those so-called inaccuracies can be fairly understood to simply be samples of the broad variety of experiences of the people and journey concerned
Their experiences, and that ethnic group generally, is every bit as diverse in its experience and outlook as the broader swath of humanity. Unfortunately, it seems that in recent years every ethnicity is assigned a monolithic identity against which any deviation is deemed offensive.
If those in an uproar over it accorded Mexicans and immigrants the respect and consideration of being a diverse group with broadly varied experiences even in the course of similar events then... well, there wouldn't be an uproar.