He knows people
He post on Meltzrs board.
Basically, he hears unconfirmed gossip & rumors & tweets them.
Guys like Meltzer, Ariel & others, hear them & look into them further.
He just post them ASAP on twitter & gets away with it bc he is not really a reporter like them.
So sometime the rumor becomes true & he looks like he 'scooped' others, but in truth they heard it before him, but were trying to verify it.
Like FRB reported that Fedor was signed to UFC
Meltzer the next day said he wasn't and that was because he heard the same BS & checked sources & found that Nu_Pride (at the time) were in the process of finalizing the deal