I doubt that thing is legit tbh, most of them aren't.
According to Forbes he owned WWE stock worth $400 million in 2011
Source
However he didn't make it into the list of executives with over $1 billion from the same time frame and needed the stock to be double what it was operating at this time to make the cut
Source
Stock traded at mid $9's at this time as seen in the above mentioned article and needed to be double for Vince to reach the list apparently, stock traded at 7.85 at close today (
Source ) So I doubt even with extra revenue streams his net worth is at the billionaire level, I speculate the $700 million mark is alot closer to the point from the limited research presented above.