It won't be a thing where you go inside the casino rather you go underground the casino so it doesn't have to be in the "door" you walk through to go into the actual main floor of the casino. It wouldn't actually link towards the casino itself as you aren't gambling you are robbing.
Summary
Within the whole Bank scene of stuff I think everyone can agree its seeing the same things over and over. People have mastered how to do most things undetected and avoid police. So this is why I think maybe introducing a new Heist into the server could be a big thing for a lot of people...