Charles Affron: Gish's story is phony, the happy ending is genuine
Charles Affron has researched Lillian Gish in great detail, here is what he has to say:
The ending of The Wind was reshot, not to provide a happy fade-out but to alter the happy fade-out that had already been filmed. All of the early drafts of the script, including draft no. 4, dated February 3, conclude with the reconciliation of Letty and Lige. Marion's own copy of the final script, started on February 14, 1927, and finished on February 24, accounts for more or less what we now see on the screen, the couple's embrace: “The wind is blowing such a gust against the window that the two figures seen inside are lost forever.” The new ending, in a script dated July 20, differs only in minor details, and in the elimination of Lige's sidekick, Sourdough, as witness to the couple's bliss. It is highly unlikely that the studio decided to use the “tumbleweed” ending after the final ending had been completed. Gish and Marion fabricated their own unhappy ending, not to The Wind, but to the story of its making. For Lillian Gish, a sellout by the front office was an excellent pretext for her decision to leave M-G-M, clad in the probity of her art. In retrospect, even the chronology worked out for her. Since The Wind was her last silent film to be released, the saga of the uncorruptible [sic] actress losing her battle against the philistine studio bosses seemed to coincide with her break at M-G-M.
Charles Affron “Lillian Gish - Her Legend, Her Life” p. 229