According to a tweeter user who somehow gets access to a leak that hints GTA Online next update will be adding a Casino in the game. The user shared a screenshot of Casino (https://canadacasinotop10.com/) building of GTA Online on Twitter and confirms that this will be definitely coming up in the next update. This can be a rumor also, but if the information is true then in coming future updates GTA Online users will shed some cash on cards.
The tweet does not reveal enough info about the future update, the user, however, got the information from background script that is locked for some specific dates and once it arrives the changes will be applied adding the new add-on in GTA Online.
There were rumors that GTAO Next Update will feature the casino, I can confirm it.
Just now, R* have updated the background script to set specific dates that will apply changes to the casino.
You'll notice changes happening near the casino as we move closer to release.#GTAOnline pic.twitter.com/nPb4V9OVg3
— Tez2 (@TezFunz2) June 6, 2019
Rockstar adds regular events and updates for GTA Online allowing player around the world to participate in a new mission and unlock amazing rewards. You can visit the Rockstars Social Club event website to find the latest information on event weeks, contest and giveaways, live streams, etc.