It was actually stated by Kevin Feige when he announced phase 3. With all the movies being put out, Feige believes that people are eventually going to tire of that formula. Besides, origin stories take up a good chunk of a movie. Instead, you could have origin stories established in a previous film, so by the time of the origin film, the hero can jump into action.
I don't remember Feige saying anything close to that.

Can you point me towards an article that quotes Feige or anyone from Marvel saying something to that effect?
The link you later provided quotes Devin Faraci from Badass Digest. While he is definitely among the more credible of the geek entertainment journalists out there, he often has a tendency to get ahead himself by mixing big dollops of speculation to go along with the actual news his sources give him.
If anything, Feige has gone out of his way to say that Dr. Strange has one of the best origin stories in comics. Even if the movie starts off in "media res" as he says, I expect them to skip back to Dr. Strange, egotistical surgeon (ala Iron Man). While it's entirely possible they skip a traditional origin story, I am pretty skeptical that they will.
Captain Marvel on the other hand, I can see them skipping the origin story or speedily glossing over it via a flashback montage. This is unfortunate because it's something that I would've really liked to get into, but my thinking isn't based on anything Faraci said, but rather due to the placement of her movie in between the two Infinity Wars movies.
I believe the big 3 (Stark, Rogers, Thor) won't be a part of A:IW1... or might only show up in a post-credit scene. So, I expect a powered up Danvers (along with the others) to go against Thanos. Lone Air Force lieutenant/captain/major Danvers going against Thanos alongside various other supers wouldn't make too much sense to me. Considering her solo comes after A:IW1, I don't think there's much wiggle room to do a full origin story there.