I am familiar with this tradition and when I was a kid I do really thought that it is a bad thing and that people should focus more with the mourn and not with activities involving money or gambling to be more specific. As I grow up and learned that it is helping the family in the wake, and yes financially. It also adds "bond" to people who attended the wake in some ways. But there are people who are not having the intention to mourn; they're only visiting the wake because of these activities. Is it a bad thing? Morally, yes however no matter how we look at it, it is indeed legal and with approval from the family of the wake..
Haven't heard of this as it's my first time and it's sounds interesting going by the motive of the organization of such gambling games under the wake. I hope people don't get too excited to wish for more of these wake's because the more the wakes the more loved ones that are lost to death.
On the bright side, the initiative acts as a succor of relief to some of the financial burden surrounding burial rites and it also while under the wake help reduce the grieve of the bereaves as they have people around to play with and forget their sorrows with some euphoria that's lifting from the shock of the loss.