No, it isnt. Ratings have dropped, and buyrates have dropped in every ppv the last years. Yeah, wrestelmania 28 had a great buyrate. But what happens when all the dream Rock, Brock, and Cena matches happens. Then the ratings will drop. The WWE will fall eventually, its only on buyed time thanks to draws like Rock and Brock.
I don't think the dream matches you list disappearing will have that big of an impact on ratings, year-round. And perhaps not even much at all. What will perhaps be hit hard as a direct consequence, however, is WWE pay-per-view. That's been the single most erosion-devastated aspect of WWE's business, and it's been declining for years now. It's why the gimmick PPVs were created, it's one reason (though hardly the biggest) why the emphasis on Wrestlemania keeps growing every single year, since it's the big honey pot for WWE every year. They rely on it more heavily today than ever before.
Yep, AE stars and Cena still pretty much responsible for WM's financial success in recent years.
It is true, to a very significant degree. Because of the mega success of Austin, WWE was able to expand. Internationally, domestically. More revenue streams opened up. The company went public. The concept of weekly Raws being live took hold. The television show Smackdown. Out of The Rock, came ever more expansion, greater success, a litany of broken records and more international strides. With Cena and Batista, even more international penetration, enormous licensing deals and even more solid sponsors, and an increase in the split roster's live events duties, as well as a more streamlined conveyor belt of merchandise than ever before.
Right now, the company is fundamentally still going based chiefly on the aftereffects of these time periods, and most recently with the return of The Rock spurring quadrants of business coupled to the stability of John Cena at the top which creates an immediate sense of order for the new arrivals and returning stars like Rock and Lesnar (Rock needed to have his match vs. Cena and Lesnar giving anyone but Cena that F5 the night he returned would have meant exponentially less).