All this article does is speculate on the statements made by the Bleeding Cool one.
Everyone is hyper-sensitive about this. And to a degree I understand. These movies are important for all of us. They are a culmination of years of our fantasies and desires ever since we started seeing X-Men and Spider-Man movies finally realized onscreen.
I think calling the film a failure is extreme. However, it would not surprise me if execs see it as a failure. Why? This is Hollywood. We have already seen how this can be like a gossipy high school. But I think it's based on the performance of The Avengers.
After The Avengers, Disney's expectations for this film were very high. When you release a film like this, the general goal is to match or surpass the take of the original, which Age of Ultron was not able to do. Reviews were not as strong either. Not to mention, Marvel had all sorts of momentum riding the wave of 2014 from The Winter Soldier and Guardians of the Galaxy. After Guardians, Marvel could essentially do no wrong. It might not seem like a big deal, but the fact that Guardians' performance made WB blink and move the release date of Batman v. Superman away from Civil War was huge. It was a battle that Marvel Studios essentially won over WB/DC.
Now do I think everyone's expectations were a little too high and unrealistic for Age of Ultron? Yes. In many instances, it is not often that a sequel in a franchise like this will top the original, especially when the original so well done and well received.
Also, the studio really spends untolds amounts of money on these pictures. This goes well beyond the production budget. There's advertising, there's the cost of wide international distribution for a major release, and then there is the actor fees. Robert Downey Jr. was paid $50 million for The Avengers. Think about that. He got $50 million for that film. Chances are, he walked away with a hefty chunk of change for Age of Ultron for his renegotiated deal. So while we might read $250 million or so for the budget, there is quite possibly a lot more expenses that make it a lot harder and a lot longer for a film like this to make money. And for a film like this, a studio doesn't just want to "break even" it wants to rake in tons of profit.