This is nothing new, it’s been going on for years.
The few examples I know of (no, not giving details!) have gone quite wrong for the casinos who bought the sites. They don’t seem to understand the amount of work that goes into it.
Buying hundreds of “three page wonders” and then buying traffic for them was possible a few years ago, but isn’t now.
Doing blackhat techniques and spamming the search engines with hundreds of sites advertising certain properties has been done and casinos who do this risk being tossed out of google alltogether. You don’t see it anymore today.
And you can’t buy a popular site and just leave it sit.
Generally casinos soon see that they bit off more than they could chew and the practice really hasn’t spread in all these years.