I thought the most interesting parts of this are where Saunders is quoted at length.
The lesson he learned was the thing he sensed all those years ago in Sumatra, reading but not fully grasping Vonnegut. “I began to understand art as a kind of black box the reader enters,” Saunders wrote in an essay on Vonnegut. “He enters in one state of mind and exits in another. The writer gets no points just because what’s inside the box bears some linear resemblance to ‘real life’ — he can put whatever he wants in there. What’s important is that something undeniable and nontrivial happens to the reader between entry and exit. . . . In fact, ‘Slaughterhouse-Five’ seemed to be saying that our most profound experiences may require this artistic uncoupling from the actual. The black box is meant to change us. If the change will be greater via the use of invented, absurd material, so be it.”