You mean that unofficially they target international audience? I am guessing they target anyone they can and hope they get away with it. But this just makes me think that they aren't planning for long time growth, because this is not the planned road. It just looks like that they want to go around regulations as long as they get away with it.
I hope you luck and that i am wrong, because i am guessing that if and when this site finally shuts down, they have planned it in a way they can disappear. And it's not like any of their users who log in via VPN would have legal claim for their money anyway.
More than sure that those formal restrictions are neglected, if not all than most of the gambling sites. As I said earlier, if gambling sites would carefully comply with the requirements and restrictions of regulators, the traffic to their sites and, consequently, their profits would be much less.
And if there is a fear of losing money because of the use of a VPN, then it makes sense not to keep funds on gambling sites that you are afraid to lose.