For Arrowverse, how do you want it's extreme expansion handled?
During the Crisis on Infinite Earths they pulled a lot more into it. Black Lightning, Batman (1966), Superman Returns, Birds of Prey (TV show), Lucifer, Smallville, Flash (90s), Titans, Doom Patrol, Swamp Thing, Star Girl, Batman (Burton/Schumacher), and the DCEU are all part of the Arrowverse now. Flash (90s), Superman Returns, and Black Lightning are all very plot relevant with Black Lightning explicitly becoming a founding member of a Justice League like organization. Smallville and Lucifer both impact the plot, but not as much as the first three. The rest are mostly cameos, some bigger than the others.
My personal opinion is that the Arrowverse fandom consists of Arrow, Flash, Supergirl, Batwoman, Black Lightning, Legends of Tomorrow, and that for the others the characters who appeared in the crossover or are explicitly named could be nominated in Arrowverse, but the base fandoms wouldn't be folded in.
Arrowverse
During the Crisis on Infinite Earths they pulled a lot more into it. Black Lightning, Batman (1966), Superman Returns, Birds of Prey (TV show), Lucifer, Smallville, Flash (90s), Titans, Doom Patrol, Swamp Thing, Star Girl, Batman (Burton/Schumacher), and the DCEU are all part of the Arrowverse now. Flash (90s), Superman Returns, and Black Lightning are all very plot relevant with Black Lightning explicitly becoming a founding member of a Justice League like organization. Smallville and Lucifer both impact the plot, but not as much as the first three. The rest are mostly cameos, some bigger than the others.
My personal opinion is that the Arrowverse fandom consists of Arrow, Flash, Supergirl, Batwoman, Black Lightning, Legends of Tomorrow, and that for the others the characters who appeared in the crossover or are explicitly named could be nominated in Arrowverse, but the base fandoms wouldn't be folded in.