J.L. Bell of Oz and Ends is far more qualified than I to discuss The Man Who Made Oz. I have to point out, though, that in the first paragraph of page two, the author, Meghan O'Rourke, uses the term "suffragette" as in "Notably, The Wonderful Wizard of Oz offered a paean to strong women at a moment when suffragettes were agitating for the vote." That always gets my knickers in a twist because my History of Women professor said suffragette was offensive. Suffragist is the correct term. At least here in the United States.
And, yes, I did believe everything my professor told me.