Even though Rockstar cut many ideas during development of Grand Theft Auto 5, they recently stated that we could end up seeing some of GTA 5's abandoned concepts through GTA Online.
Speaking with Edge, Rockstar North art director Aaron Garbut noted that GTA Online will allow for many new additions and the ability to incorporate content that was originally planned:
"As a group of people, we’re never short of ideas. There are always things that come up during development that you want to add. Often we do, but the closer you get to release, the less that happens. I don’t feel like the game fell short, but there is undoubtedly a huge volume of plans and ideas that we wanted to do to push it further."
"That’s even more exciting these days, where through forums, Reddit, etc, we have a real direct connection to the people playing the game. We can respond to what they are into and what they hate more than ever. It’s something that really suits the way we work, the way we’re always trying to adapt the experience and avoid walking blindly down a set path."
So it looks like we could be seeing a lot more content added to GTA Online this year, which is good to hear, let's just hope the online heists will be here soon, because that is what most of us want.