#2 Almost as big a mainstream name as Jericho
Dean Ambrose was a part of the greatest faction of the modern era- The Shield, and he still left the company for the greener pastures of AEW. Even though Chris Jericho is a man whom fans know from his stints in WCW and NJPW, WWE is the ultimate destination for any professional wrestler in terms of worldwide acclaim. The title was put around his waist because of the fact that he is a global draw.
And because the title was taken from Chris Jericho, it had to be put on someone that the audience may recognize, that they may gravitate towards. It is the same way that Hulk Hogan became the heart and soul of WCW after he made his way from WWE to the company in the 1990s. If the audience already knows one of your top stars, half your job is already done.
We will wait to see if AEW can maintain its dominance on Wednesday nights over NXT now that Chris Jericho is no longer the Champion.