His Name Is Not Hal Jordan It's Alan Scott, Even though on the Cw the flash episode Welcome to Earth 2 they teased Hal, it does not mean that Hal Is the Green Lantern.
After nearly dying in a train crash, Alan Scott was given the power of The Green Lantern, to fight the threat of the villain The Grey. Alan Scott was a young, openly gay media mogul, who dedicated his work to the heroes who gave their lives three years prior in the war against Darkseid. The Grey chose Grundy as its champion, and the dead man began sending the force of decay throughout the earth to get the attention of the green lantern.
Alan, upon seeing the destruction caused by Grundy, went to confront him, and was joined by other heroes; The Atom, Hawkgirl and Flash. So He Is Friends With Jay Garrick and The Atom who is named Albert Pratt and Still Kendra Saunders. So he knows the heroes we have seen in the Flash. But Earth 2 Green Lantern is not Hal Jordan. Abilities the same as Earth 1 Green Lantern. But They Still could add Hal as earth 2 Green lantern still because they do the wrong stuff all the time. Like how they stole a bunch of stuff from Batman for Arrow.