As much as everyone - myself included - would LOVE to see the Ayer Cut amongst others, the best we can ask for from a "DCEU ultimate collector's set" is more deleted scenes.
I know James Wan isn't the kind of guy to put out deleted scenes for his movies, but I'd like to see the most interesting one where Arthur learns to breathe underwater.
There's also one from BvS that didn't even make it into the Ultimate Edition. As quoted by director Zack Snyder in an IGN interview:
On the topic of Snyder's DC movies, we've also yet to see what was cut from Man of Steel, although some of
those scenes are featured in the novelisation.
In the case of ZSJL, I've heard unsubstantiated rumours that there was a scene involving an Amazonian warrior who gets infected by the energy from Steppenwolf's Electro-Axe and promptly kills herself before turning into a Parademon. Now I don't know if this was something Snyder initially had in mind but cut either early on or out of respect for his daughter after her suicide in March '17, or if it was a Joss Whedon addition that he was forced to take out to meet WB's 2hr mandate. Either way, we can't be too sure.
Sam Benjamin also stated in an interview with Comic Consultant that the studio cut 20-30 minutes of a military subplot from the final release:
What baffles me about this is that he BARELY appears in ZSJL. Is it possible he misremembered the extent of his involvement with the picture? Or is WBD holding off on sharing the footage for old times' sake?
Oh, and #ReleaseTheGreenLanternScene.
Speaking of Joss Whedon's Justice League, I found out on Reddit just last month that there exists an early cut of the movie called "Joss Cut 1". It consists of "B Revision 2", the last cut Snyder worked on before Autumn's death, with Whedon's notes and reshoots
fully implemented. It's common knowledge that the opening scene on the rooftop was edited down from its initial rough cut, as revealed by Holt McCallany in a Variety article published a week after JWJL's release:
Other than that, God knows what Joss had to trim away from his rough cut - or if it would've made for a decent product in the end (probably not lol)!
Let's also mention the R-rated cut of Black Adam. I imagine The Rock's ego will prevent this version from EVER seeing the light of day, but you never know.
And don't even get me started on The Flash! Aside from the 14 minutes included on the Blu-ray disc, they shot a lot, a LOT that got cut: "R-rated" fight scenes between Supergirl and Zod, 2023-Barry and Dark Flash duking it out, additional cameos during the Chronobowl sequence, multiple endings featuring heroes old and new, an alternate post-credits scene involving Batfleck getting lost in the multiverse, the whole nine yards!
Barry vs. Dark Flash BTS:
I could keep going, but we'd be here all day.