It’s known that WB CEO Kevin Tsujihara mandated Justice League come in under the two hour mark, so it’s safe to assume lots of footage didn’t make its way into the final cut of the movie, which not only included all the Zack Snyder footage, but Joss Whedon’s reshoots as well.
A list of Zack Snyder deleted scenes can be found below in addition to scenes featured in various trailers, but not in the movies.
Hopefully the Justice League deleted scenes are released as part of the Blu-Ray.
A Parademon scene. The Iris West deleted scene with Ezra Miller and Kiersey Clemons.
Ray Fisher Cyborg scene.
Another Ray Fisher scene as Victor Stone.
Cyborg flying scene.
A Cyborg computational scene of some sort.
Justice League Mother box scene.
The Link to video above