HBO Max's Green Lanterns, but not Hal Jordan and John Stewart, which is the right thing for the show to do, at least for the beginning. Arrowverse creator Greg Berlanti's next DC TV project will be the most ambitious one he has ever done, with HBO Max bringing the Green Lantern Corps to the streaming screen and reaching new levels with the series. While the show won't be set on Earth-Prime with the other Arrowverse heroes, Green Lantern is part of its Multiverse by originating from Earth-12. What's more, instead of one, Green Lantern will focus on multiple iconic Emerald Knights in different time periods.
Since the Smallville cameo and the not-so-beloved Justice League of America pilot that Guy was in, they haven't had any big media appearances.
HBO Max starting Ms. Marvel series, Muslim superheroes and superheroes of Middle Eastern descent are something media lacks greatly. Thanks to Green Lantern, Simon will finally jump from page to screen as a Lebanese-American Green Lantern who is also Muslim. The series is also including the LGBTQ+ community by featuring Alan as an openly gay man who was Earth's first Green Lantern.
Green Lantern will allow audiences who may not be comic book readers to get to know these characters, who deserve to stand on their own. There is also nothing stopping John and Hal from being introduced later in the series, especially if Green Lantern Corps eventually connects to the TV show since HBO Max and DC Films are working together. If the DCEU project doesn't happen, after all, it could open the door for Hal and John to appear in the HBO Max series. But letting Alan, Simon, Jessica, Guy, and even the new Lantern, Bree, be in the spotlight, they will get their own followings. That would be a stable path to start on before bringing Hal and John into Green Lantern, which would be incredible as it would unite all of them, especially if they were to later add Kyle Rayner, too.