the implications of SPOILER becoming the DCEU Batman (Spoilers)
George Clooney is now the DCEU Batman at the end erasing Affleck and replacing Keaton who had originally filmed the final scene with the new SG (before it was reshot with Cavil/Gadot showing up, then again with Clooney). Keaton would then have been the 'new' DCEU Batman appearing in the shelved Batgirl with JK Simmons as Cmsr Gordon, cameoing in Aquaman 2, and potential Batman Beyond movie
So now it means 1997s Batman & Robin is now canon in the DCEU backstory for Batman (which also means variations on the previous 3 Batman movies which now had Clooney in them) so that means Chris O'Donnells Robin was potentially murdered by the Joker shortly after B&R (Jack Nicolson's Joker possibly wasn't killed at end of Batman 89?, as Clooney would have a slightly altered past/universe as we saw with Keatons Batman), Clooney Batman faced off against Cavill Superman and flirted with Gadot Wonder Woman in BvS, beat up Will Smiths Deadshot (and Nicolson Joker, who has Margot Robbie as his Harley) in Suicide Squad. and brought back Superman to take on Steppenwolf in Justice League (both versions)
Regarding the potential future of the DCEU in the inevitable Crisis on Infinite Earths movie in a few years time headlined by new DCU actors but featuring the previous DCEU actors (like happened in Spiderman No Way Home, The Flash and will be done in Deadpool 3/Avengers Secret Wars) obviously wed see Affleck return as the DCEU Batman (the explanation being Barry simply went back and changed it so Batfleck returned)