Pretty sure virtual gambling only gets murky once real-life money enters the equation. If you're spending cash for gil, and then frittering it away, then the lawyers' ears might perk a bit, but officially in this game it is not allowable to trade real-life money for gil. A way to gamble away in-game currency isn't even gonna ding their radars.
And, to be fair, even if real-life money is involved those ears might perk, but not by much. Gacha-based mobile games are a huge thing right now, and that's almost explicitly spending real-life money to spin the virtual roulette wheel. If the legal train gets rolling, those will definitely be the first stop.
