Joker famously set itself apart from the DCEU by painting a vision of a darker, more grounded version of the DC universe. In the film, Thomas and Martha Wayne are still slain in front of their son while leaving the theater, however they aren't killed by Joe Chill this time. The Waynes are killed by a rioter in a clown mask, who was inspired by Arthur Fleck's murder of three Wayne employees on the Gotham subway, and by his public execution of late night TV host Murray Franklin.
Arthur Fleck unintentionally started a class war in Gotham City, and by the end of the film there's no indication that it will stop any time soon. This universe's Bruce Wayne will grow up in a Gotham very different from the one traditionally shown in other Batman media. Many fans wondered what future lay ahead for Bruce, and if he would ever cross paths with Arthur in the future.
Meanwhile, 2021's The Batman is filming currently in the UK with Robert Pattinson. As was announced a few years ago now, this film also appears to be isolated from the DCEU, and this has led fans to wonder if perhaps it could take place in the same universe as Joker, albeit a few decades later. Could this Batman be the same Bruce Wayne whose parents were killed because of the riots Arthur started?
It's certainly possible, and fan artist Alex Kovalenko seems to agree. He created some stunning artwork depicting the characters together, and honestly, they look great together.
Robert Pattinson and Joaquin Phoenix are both some of the most talented actors of our time, and it would be a gift to audiences everywhere to put them on screen together in any movie, especially one where they play Batman and Joker. The added knowledge of Joker being responsible for the riot that claimed the lives of Bruce's parents would make the classic rivalry between the two characters far more personal.