#5 Dean Ambrose
After last week's episode of Raw, reports came out that Dean Ambrose would not renew his contract and that he would leave WWE once his current deal expires in April.
He was disappointed with the lack of creative control he had with his character and seemed like he had enough of it.
Should Ambrose indeed leave at the end of April 2019, he could be one of the first chips to switch promotions.
While he likely wouldn't be able to be on TV and perhaps at Double or Nothing due to WWE's standard 90-day no-compete clause, he would certainly be able to make an impact over the summer.
He would be a main-event caliber talent that could instantly challenge for any promotion's major title.
Since Cody has worked with Ambrose before, he might give him more character input in AEW than he has had in WWE.
A truly unpredictable, unhinged Jon Moxley would certainly seem less like a PG version of the character and more so an amped-up version of the persona that got him signed by WWE in the first place.