That's normal style in mainstream journalism, weird as it is. If you read a lot of sports journalism for example, you'll see a ton of articles which are literal

That's normal style in mainstream journalism, weird as it is. If you read a lot of sports journalism for example, you'll see a ton of articles which are literally just a summarized transcript of a phone call a reporter got from an agent, written as if it's just pure factual information that appeared from thin air. At least in those cases it's trivial to guess who the source actually is. Again, it is objectively very strange to not even hint at what the source of your information is. But it's also standard practice.