I totally agree with this.
These kinds of contests (wagering leaderboard, high multiplier...) are the most effective promotional strategies for attracting gamblers and turning them into loyal customers.
The big reason for this is because of how engaging they can be. Gamblers will not even know when they are becoming loyal customers because these promotional strategy will have them always wanting to come back to the platform.
What makes them even more attractive is when they are offered exclusively to a certain community. This makes the community members feel special and know that the casino values and cares about them. They create some kind of social relationship between the casino and the members of that community.
For a casino to have a special contest tailored specifically for members of the community amongst the numerous numbers of gamblers worldwide, it's a gesture that many gamblers in that community will appreciate.
It shows that the casino values the inputs of the community and holds them in special regard.