I see this meta post
But does this make all casino style gaming on topic here? There is an Expert Casino Gaming and Gambling in Area 51, but it isn't gaining much traction.
That question/answer specifically means that tabletop dice games on topic; what you're asking about is not just dice games. The full version of the criteria it mentioned for board/card/dice/tabletop games on topic here:
A game must meet all of these in order to be on topic.
Sports betting and horse gambling most certainly do not meet these criteria. It sounds like keno uses a computer, so it's also off topic.
Roulette... could I guess be on topic? It fits all the criteria. I don't think it sounds like a terribly interesting game - you're not making really meaningful decisions - but the criteria don't require that. See also Are questions about “games” that require no decision-making acceptable? - it's asking about games like Candyland, which we've decided are fine.
So in the end, a lot of the popular gambling games are on topic here - because they have a board/card/dice game component in addition to the fact that people wager money on them. But wagering money on something doesn't make it into a board game; gambling in general is not on topic here, and if you want to talk about that, you'll want to support that proposal you mention.