How do dirt sheets work?

Hey Scott,
Avid reader here, thanks for all the years of entertainment. Question for you: How do wrestling news sites work like Dave, Wade Keller, etc? The recent topic of the Undertaker’s upcoming WM match with a non-roster wrestler got me curious. Using this an example, how does Dave or any other supposed credible news site gather information? Obviously I’m assuming Vince starts at the top, and comes up with the match. But if he wanted to keep it a secret so badly, why doesn’t he just have a meeting with HHH, Undertaker, and the opponent, and tell them not to tell anyone?
How do these rumors always inevitably get leaked? Or do news sites just make up BS because they know people will come read about it?

​Well Meltzer in particular has people in WWE who are constantly calling him with info and news, and I imagine Keller is the same. ​Dave used to talk to Vince all the time, but mentioned recently that it’s been a long time since they’ve spoken. Typically all others flow downhill from those sources. Others do just make stuff up, or wait until sites like mine break "news" and then rewrite it while misattributing everything and completely missing the point. Your mileage my vary.