Warner Bros. Discovery kicked off its annual upfront event at the Madison Square Garden Theater by paying tribute to the late Ted Turner, who had just died the previous week. Turner, of course, was part of why WBD was even holding an upfront in the first place: Not only was the media giant a cable pioneer who brought us CNN, TNT, TBS, Cartoon Network and more, but his Turner Broadcasting was the cornerstone of Warner Bros.’ ad-supported media portfolio — something that expanded greatly with the Discovery Communications merger. But as Anderson Cooper paid tribute to Turner, the audience of ad buyers, media analysts and reporters couldn’t help but think about the elephant in the room — or, as WBD’s presidents of U.S. advertising Ryan Gould and Bobby Voltaggio joked, the “Ellison in the room”: This wasn’t just a eulogy for Ted Turner. It could very well also be WBD’s swan song, as the company will likely be consumed by Paramount Skydance before the next upfronts season.…