Is there clear plagiarism? The Great Depression wasn't exactly an obscure topic and was still fresh in the minds of many people at the time.
What is going on? Is this posthumous cancel culture?
Wasn't it prudent to look for similar media and clear the wake? Publishing was a smaller, more difficult world back then and publishers wouldn't back two of the same thing.
Wouldn't you drum up support for the novel you worked on? Especially after having struggled for years as a manual laborer trying to make it? Would you willingly table your book that you worked on so that someone else could take your place?
Is that malice?
Unless there's clear evidence, it's like saying Marvel plagiarizes DC. And that Disney should be cancelled for scheduling their movie premieres around the best moviegoing dates. (Is that highly competitive? Sure. Evil? no...?)