The Flash was such a nightmare, it went through three different studio regimes and had three different endings.
In all three endings,[Spoiler (click to open)]Barry gets his father exonerated and released from jail, but still doesn't fully reset the timeline like he thought.It's after where things get wildly different.
Ending 1
Under the supervision of Warners studio head Toby Emmerich and DC Films Walter Hamada. Pre-WBD merger.
Hamada wanted Flash to be a major reset, have a sequel, and then move to Crisis on Infinite Earths.
After leaving the courthouse, Barry meets Calle's Supergirl and Keaton's Batman, reversing their deaths and keeping them in the main DCEU.
Ending 2
Under the supervision of new Warners studio heads Michael De Luca and Pamela Abdy. Post-WBD merger.
Same as Ending 1, with Henry Cavill and Gal Gadot tagging along.
Ending 3
Under the supervision of new DC Studios heads James Gunn and Peter Safran.
This time Barry only meets Bruce, played by George Clooney.
Gunn and Safran winged it, called Clooney's agent (Bryan Lourd) and got Clooney to watch. He liked it, so he did it.
Ending was shot in January, took a day on the WB lot and the Clooney reveal wasn't fully shown until press screenings last week.