Two thoughts…
First off - AEW has the most absolutely stacked male roster I can think of since WWE in 2002/2003 in terms of proven star power and draws. The roster depth is insane… Punk, Bryan, Omega, Bucks, Sting, Moxley, Jericho, Hangman, Keith Lee, Cole, Andrede, Black, MJF, Sammy, Darby, Starks, PAC, Miro, FTR, Lucha Bros, Orange Cassidy. There’s a dozen more ready to step up. The female roster is slowly building into a terrific division as well.
Cody isn’t needed. Removing him doesn’t hurt the rest of the show. And while his matches were usually excellent, 80-90% of the non in-ring stuff he was doing, was usually panned by nearly everybody, and booed by fans.
I think it’s also very fair to say that Cody’s programs for the last year (more or less since his second TNT Championship reign), have felt very shoehorned in at the expense of everybody else. His QT Marshall feud. His Anthony Ogogo feud. His Shaq match. Rhodes to the Top. The rivalry with Black and Andrede did nothing for him, and most people saw it as a negative for all of them.
He puts on amazing performances match after match (which he won’t be able to really do in WWE)… but he’s earned the right to enjoy a payday and work some chinlocks with Randy Orton.)
“You either die a hero or live long enough to see yourself become the villain” - that defines Cody’s run in AEW.
Secondly - the idea of talents jumping between promotions is very welcome and a great reason why the 90’s was such a fun time to be a fan! People who weren’t working in one place went to another place and got a shot. Undervalued talents had options. AEW has added so many people (and I fully expect to see the Jeff Hardy and others soon to pop up), just like I’m sure some people will end up in WWE who have spent time in AEW.
Off the top of my head, you could cut Cody, Jericho, Hagger, Brian Cage all tomorrow and there wouldn’t be a dip in quality or fan interest.
Cody won’t be the last - but there are tons of people elsewhere ready to jump into his spot as well a dozens already there willing to step up.