No sir, the WWE is not in trouble. Yeah, the product could be better, but it is no where near the wrestlecrap it was in the mid 1990s. I mean, King Mable was main eventing for Christ Sake!
What I find hilarious is that so many people where talking about how boring and soft Dean Ambrose was a year ago, and now those same folks are saying he is the greatest thing since Sliced Bread because he went to another promotion. Man, get the hell out of here with that nonsense. He is still the same lazy, soft putz he was in The WWE. What does that really say about your upstart promotion when the guy who was going to be jobbed out to Nia Jax is considered one of your top guys? Yeah, some Anti-WWE Smarks will eat it up (those same ones who complained about Dean in WWE by the Way), but will John Moxey really bring in that many fans? This guy is so delusional, saying he was the most over baby face as a heel, at house shows during his program with EC3. No you wasn't pal. Some of us where in those arenas, and even Virgil would have gotten a bigger pop than you did.
Also, who cares if all of those disgruntled wrestlers leave? WWE have more than enough to cover down their spots. Most of them are boring jobbers anyway.
This all just feels like you trying to be the anti-smark. People loved Dean Ambrose from the jump in WWE. He was the most over guy in The Shield in the beginning, but Vince made his mind up that he saw Reigns as the cornerstone for the future. Triple H took a liking to Rollins. Ambrose ended up being the odd man out for one reason or another and his career just steadily declined, particularly after his WWE Championship reign ended. Everything that people, generally speaking, grew to dislike about Ambrose were things that writers pushed on him. Even in 2018, people were excited for him to return from injury and were losing their shit when he turned on Rollins, only for WWE to hand him that germaphobe gimmick that went over like a lead balloon. A gimmick, mind you, that he didn't want to work. I don't know how you can think that him being BOOKED to job to Nia Jax after putting in his notice says anything about his star quality either, by the way. Says a lot more about WWE being bitter that this guy has enough faith in himself to walk away from the biggest company in the world, and maybe that they wanted to dim his shine a little bit more on the way out even.
I totally understand that these people on the internet, particularly the social media types, say a lot of dumb shit about WWE and AEW. And they can be annoying. And they can turn you against AEW. And I feel like that's what this boils down to. Dude had a great independent career and a hot start to his WWE career. There are some people like myself who have been a fan of him for over 10 years and are excited to see what he can achieve now that he's been left off his leash again. You'd have to be paying no attention to think that him coming to AEW didn't cause a huge amount of publicity because it did. It was the biggest thing that happened on the show. A show that had the highest PPV buyrate of any non-WWE company since WCW in 2000. I've personally seen a few fans online already saying that Moxley's surprise appearance has convinced them to check out AEW. Don't get me wrong, I don't think Vince is losing sleep over any of that, but that's nothing to sneeze at either.
And having said all that, I will address the original question. No, I don't think WWE is in trouble at all. I would imagine it would take a very long time for a company like WWE to crumble and for a company like AEW to become an actual threat. Anyways, the company is the biggest its ever been, they have a thriving streaming service and unprecedentedly lucrative broadcasting deals. WWE does have its issues and maybe if it goes long enough without addressing them, they'll find themselves in some hot water, but as of right now, they're going to keep on trucking along until they're forced to switch things up. There's a whole left to be seen as to whether AEW will be a successful company, much less any kind of competition to the juggernaut that is WWE.