Nobody here has engine access, sure. But that doesn't suddenly make 60fps likely. It just means we fall back on precedent and known constraints.
Rockstar has never launched a GTA or Red Dead game at 60fps on console. They've always prioritized world density, simulation, AI, physics, and visual fidelity over frame rate.
GTA is also largely CPU bound, not GPU bound. PS5 Pro mainly helps on the GPU side, and GTA's traffic systems, crowds, physics, and world streaming are exactly the kinds of things that tend to lock these games to 30. That doesn't just go away because of "optimizations."
On top of that you have the scale of a dense open world city, the need for consistency with GTA Online, and Rockstar's long standing design priorities, which have never really been about chasing high frame rates.
Could there be a compromised performance mode? Maybe. But based on Rockstar's history, CPU limits, and how these games are built, 30fps at launch is the reasonable expectation.
I'd love to be wrong, but hoping for 60 and expecting 30 feels like the realistic position.