The Black Lighting is coming the the CW this fall and there are no plans for Black Lighting to be part of the Arrowverse. According to network president Mark Pedowitz that there will be another Arrow/Flash/Supergirl/Legends of Tomorrow but Black Lighting will be in another universe.
One of the reasons that Black Lighting will be set in a different universe is the location. Black Lighting will be filmed in Atlanta while the other shows are all in filmed in Vancouver. So doing a cross over can be a little difficult with all the travel.
My feeling is the show will take on the same theme as the other show have of protecting a city. After watching the trailer I did get a Luke Cage feel for it. Unlike the Luke Cage where Luke is interested in protect Harlem, Black Lighting will be protecting his city. Black Lighting maybe the CW’s attempt of getting some of the same audience as Luke Cage. My feeling is that the ability of Marvel to go a little darker on Netflix will give Luke Cage the edge.
The show does have something different from the other shows on the CW. This show leads are black and hopefully it tackles some more adult stories and not worry about the pretty young people. Tackling what it is to be a black vigilante that is a hero and the struggles it is to be one. Time will tell if the audience will jump on board and follow another superhero show on the CW.
Black Lightning is a super-hero with the ability to generate and control lightning. Originally he was a high school principal and Olympic-level athlete who became a vigilante to take down organized crime in Metropolis‘ Suicide Slum. Eventually he would become a member of Batman‘s team of Outsiders for many years, although he retired briefly to become secretary of education under president Lex Luthor. He returned to crime-fighting, though, as a member of the Justice League. His two daughters operate as the super-heroes Thunder and Lightning. Black Lightning was created by Tony Isabella and Trevor von Eeden, first appearing in Black Lightning #1. (1977)
Source: io9, DC, Youtube