Just when I thought I was out... they pull me back in. Rockstar are giving players an incentive to jump back into GTA:O with double GTA$ and RP. This definitely indicates that the next patch is coming up soon.
I would say that the next patch will be within the next two weeks. Given that each update seems to be early - mid month, every month. That would mean in a little while we will have the high life DLC and in just over a month we will get Heists. Calling it right now: June 11th is heist day.