The Orin ending (tumbler-and-roaches) was a requested insertion, faxed June 11, 1995…
This is material that was added after the early draft: absent from the 1993 manuscript, present in the published novel.
In the manuscript. MS-1994/95 gave no indication of Orin's fate; Pietsch "asked for one clarification… some indication of the fate of Orin."
In the published book. Scene 184 (pp. 971–972)
Evidence. A single source reports this. (archive-sourced, with the fax date). Documented by D.T. Max's biography of Wallace.
Bears on. This difference bears on the following open questions: Orin's end (roach tumbler, torture, "Do it to her!").
Further notes. The only piece of ending-cluster resolution that exists because an editor asked. Mirrors the fate Orin inflicted on the roaches — the mirroring was the pitch, not an accident. Wallace's stated qualm belongs in any orin-fate adjudication.