As in real life versus video games. I can go to an arcade and pay 25 cents to $5.00 to play a game. These arcades are made for players of all ages. Thus if UO's new "Live Team" wishes to develop a casino style gaming facility following a similar model there is no reason UO would have to be rated mature to buy or play.
For instance, I know that an NPC Casino could involve paying gold (like cash) for each chance to play a one player game like many arcade games such as skee-ball, if you do well you earn tickets. These tickets (like casino chips) can be accumulated in great quantities so that inevitably they can be handed in for prizes. Even placing bets on the outcome results of PvM gladiator style fights could be done in the exact same way based on the difficulty of the monster versus the Unknown Player based on UO calculated odds of player skills versus random monster skills.
The anonymous Unknown Player is key. This means instituting a que system much like GM wait time that doesn't reveal your actual wait time. When you enter the arena, players can only see generic looking character fighting the monster, but have no clue who the contender is. Thus no rigging the system. Create negative effects on characters who lose, lose a lot, and lose all the time.
The collection models at the library, museum, and zoo have a very similar concept, except that it is guaranteed so many resources/gold for this such prize. While most casino games are based on luck which could be quantitatively be integrated into some of the games. Thus creating another reason for Luck armor. In addition, some games could be set aside to include ways of cheating based on a thief's skill check for snooping the deck, stealing/switching the dice, and/or not limited to bluffing.
Now what kind of games would be appropriate for players of all ages? Lets come up with some ideas to help the development team out. Imagine some simple concepts first. I personally believe in more multi-player interaction the better. I also like scaled competition where there is a starting season and end season in relationship to rank & score. In addition games geared towards every player's character template would be an exceptional bonus.
The Umbra Arena would be one good place to start for PvP & PvM.
Buccaneer's Den is definitely an excellent idea for cards, dice, and roulette.
Luna's Bag Ball Arena could be used and expanded.
Wind could have an exclusive wheel of destiny, random good & bad results.
Tokuno could have Asian style gaming for ninjas & samurai.
The more variations, styles, places, the better, and wait times can be instituted for crowded games so everyone gets a turn in the que. No different than waiting on a GM.