Believe it or not but most reporters still use the idea of private news email discussion lists from the 80s early 90s internet. Some archive them on websites but most do not. During #gamergate the gaming press had theirs exposed by a leak. This is how we know for a fact that a progressive PR firm that Anita Sarkeesian consulted for and Zoe Quinn was represented by wrote a lot of anti bro-gamer stories. Emailed them to the press and let the reporters upload it as their own original news story. Someone with access to the email list then exposed the website they automatically archived it on to reddit. Very few covered the story in the mainstream or gaming press because they also use email lists and considered it forbidden to talk about otherwise someone might do the exact same thing to them.
I hope this answers your question about how some news stories from vastly different websites/newspapers sometimes all appear at once but are not considered important enough to be embargoed by powerful companies and sources like governments. They stay connected by email lists and the PR people use them because its a private method of talking to journalists that is typically encripted and not controlled by the companies they work for. By letting 30-50 reporters (or more) have access to each list a lot of people know exactly what was said to whom if the PR people or government officals try any bullshit and lie after the fact. These services are provided by very small intimate botique ISPs who also tend to run bots and spam scripts for hackers/spammers.