Casino has to maintain and improve the product, casino has to pay salaries, marketing, bonuses and so on. What is player's duty? To win, just to profit, but casino on the other hand, has to spend significant portion of its profit on many things. That's why I think that 0 house edge is a risky thing for casino but I can be wrong.
The 0% house edge for those games aren't going to be risky for Monk.gg. You are already aware of the
2% exchange fee of the MONK token. Those 0% HE games might attract some gamblers, and they are forced to use MONK token to play those games. Which will work like a free marketing system of their tokens.
Users aren't going to get any bonuses by wagering on those games as the HE is 0%. MONK token bets are excluded from their challenges. Moreover, there will be no referral commission for the wager on those games. So, the 2% exchange fee of the token is enough to maintain the cost of those games.