Ray Fisher has barely worked since 2017's Justice League, which filmed in 2016. He has worked on one eight episode TV show since and doesn't have any upcoming credits. Something's Fisher-y.
Joss Whedon has worked with the same actors and writers for over two decades, many of whom are now famous or in-demand writers, but they still return to work with him.

Not one Justice League co-star has backed-up his claims. No one.