When Zack Snyder was still directing Justice League, Kiersey Clemons shot a cameo as Iris West. But replacement director Joss Whedon apparently excluded the scene from the movie's current cut.
Since Clemons landed the part in 2016, we’d been hearing rumors that Iris West would appear in the November 17 release. The actress confirmed the rumors in June of 2017, and recently described her scene as "f*cking sick".
A couple of days later, an online report suggested that Warner Bros. had held a test screening for Justice League, and audience reaction was largely positive. Most recently, Batman-News reported that Barry Allen’s love interest was nowhere to be seen in the screened version. It was also reported that Lex Luthor (Jesse Eisenberg) didn't appear, although he had filmed some scenes.
With new reports popping up every now and then about what Joss Whedon is doing to fix Justice League, it’s safe to say that the new director might be steering the movie away from Snyder's vision. While that’s entirely possible, we can't be sure whether those scenes would have survived with the original director at the helm. In case you don't remember, Snyder removed Jena Malone's cameo from the theatrical cut of Batman v Superman: Dawn of Justice, but then included it in the Ultimate Cut.
It’s also possible that the current Justice League cut isn’t the actual final product. There's still around two months to go before the movie rolls into theaters, so we could still see Kiersey Clemons' Iris West, Jesse Eisenberg's Lex Luthor, or maybe even both.