I don't know if they said they'll add this, or there's a thread.
I'd think they should add a bank heist callout, like in Three Leaf Clover.
It could go down with 4-8 members?
When you arrive at the bank, other LCPD / NOOSE will already be there or start arriving there.
The robber's could use the skins from the mission three leaf clover, there's 4 models of it, or 3.
Once you arrive, the robbers start shooting there way down the alley way just like in the mission, and then arrive at a Van and try to escape to a hideout. IF you still failed to kill them, more of them will be at the hideout, making a big shoot-out.
edit: And this is ment to be for GTA 4.