According to Wrestling Observer Radio's Dave Meltzer (h/t Joshua Gagnon of Wrestling Inc), Punk was the "first pick" for Khan.
AEW obviously didn't land Punk, instead turning to Chris Jericho, Cody Rhodes, The Young Bucks, Adam Page, Pac and Kenny Omega.
Punk is exactly the person to whom Khan should have reached out, though. He still remains a big star despite being out of wrestling for years, so he would've brought significant attention to the company. At 40, Punk still has some good years left in the tank as well.
He actually made his return to the ring over the weekend for independent promotion MKE Wrestling. Nobody in attendance could tell it was Punk because he was entirely covered, but Meltzer confirmed The Straight-Edge Superstar showed up without any warning.
Meltzer added Punk's appearance "is not a sign he wants to get back to pro wrestling."
Of course, wrestling fans have been conditioned over the years to question almost everything they see and hear. The truth can sometimes be elusive in the industry.
Punk told MMA Fighting's Marc Raimondi last November he'd at least entertain a discussion with an AEW representative about potentially joining the company. He also refuted the rumor Rhodes had made an offer to appear at the All In pay-per-view, which took place outside of Chicago in September.