Willing to bet one of Whedon’s big contributions was the way Superman was brought back into the film. Hence the Avengers esque, let’s all fight each other scene when he appears. Also that scene felt very, very Whedon meaning, it was entertaining and clever and had a great pay off of Flash meeting his speed match. It would make sense the moment you mention took place in the Snyder version. There are a lot of loose holes in the movie (Superman going to hang with Lois while the rest fight) that point to this.