The move they took is indeed a good one in forcing the hand of the casino owners, and I come and register and fully be regulated. That's if they value the population of gamblers. From there, some business owners just don't want to pay tax and follow laws.
Some among the 2000 will definitely comply with why some will want to leave the market or will want to operate illegally using whatever means they know, which will be a double risk to them.
Brazil is definitely more strict about regulation on the web than many other countries, even if you consider their recent blocking of X, this is one example of how they want to regulate everything that happens on their territory. Maybe it's a tax issue, maybe it's a security issue, I think that's what they'll cover, but I also assume that not everyone will want to allow regulators to interfere in their affairs. After that, we'll see how many of these 2,000+ companies return to work in Brazil, this will be an indicator of who is ready to accept the new conditions.