The wrestler behind the mask is CM Punk. MJF first wore the mask at All Out 2022, a show that ended with MJF revealing his identity and challenging Punk for the title. The entire CM Punk drama has been a work. People only believe it because they secretly or not so secretly want AEW to fail so nothing negative about AEW is examined critically.
Even though WWE generally and Vince McMahon specifically have been accused of all sorts of awful things over the years, people were either firmly on the side of WWE or ambivalent about CM Punk after his contentious exit in 2014. Americans are taught that people who complain about working conditions or how their boss treats them are whiney, ungrateful, malcontents who don't know how the real world works so this isn't surprising.
Before AEW even started the internet wrestling community has been predicting its imminent demise. Every negative rumor about AEW is assumed to be true. Every AEW wrestler is supposedly desperate to go to WWE even though only two people actually have and many of these people keep signing contract extensions. So AEW is a Kafkaesque nightmare? Is it like the Hotel California? Once you show up backstage you can never leave?
I was a lapsed wrestling fan for years because I feel like WWE insults my intelligence and their editing style and presentation make my non-neurotypical brain overload but also because it's hard for me to enjoy a show knowing so many of the performers are unhappy and mistreated. I don't judge people for liking WWE but I'm glad I don't have that baggage because it made it easy to see that the backstage drama at AEW is a work.
The two most telling signs that it is a work are: the perfect timing of each new twist in the story and the fact that nothing has been said about the CM Punk situation on the record. Ace Steele showing up on TV just in time to get fired is an obvious example but there are countless others of the perfect timing. How about Tony Kahn announcing Punk's firing on Twitter and television? Wrestling Twitter is often kayfabe and the events that take place on AEW television are kayfabe. You also release a wrestler not fire them.
The man behind the mask is definitely CM Punk. He was never in trouble backstage and people only believe it because they always believed CM Punk was the problem, not Vince McMahon. I'm guessing we get the masked wrestler vs MJF at Full Gear but I obviously have no idea. CM Punk recently said he has about two months on his hands. While many assume he was referencing Survivor Series and a return to WWE, the timing also lines up with Full Gear.