The review mentions it as an afterthought. In its opening section, the author writes:
There’s no redemption here, no moral uplift, no lessons save for perhaps the grimmest and most nihilistic “lesson” I’ve ever encountered in any story, Holocaust-related or otherwise: that when confronted with the unthinkable, most people’s natural tendency is denial.
And when discussing the actual lives saved:
Rudi and Fred do achieve one small victory: in reaction to their report—and to Roosevelt’s warning that the U.S. will punish Nazi collaborators after the war—the Hungarian regent stops deportations long enough to save an estimated 200,000 lives.
(The review mentions that too.)
The review mentions it as an afterthought. In its opening section, the author writes:
And when discussing the actual lives saved:
200,000 lives is not a small victory to me.
I agree it’s not a small victory, e.g. it’s in the ballpark of GiveWell’s lifetime impact.