It's not too early and is very easy to make a judgement.
The upgrade in CPU is nothing, and unless Rockstar have designed GTA6 to be a 60fps game from day one (highly doubtful), you're not getting 60fps in GTA6 from a CPU point of view on PS5 Pro. Rockstar have never released a new GTA game that's 60fps, they have all been 30fps and I seriously doubt they will break that tradition with GTA6.
From the GPU side, if base PS5 is 30fps and upscaling from 1080p or lower, you're not getting 60fps in PS5 Pro as the GPU upgrade isn't strong enough. If base PS5 upscaling from 1440p or so at 30fps then PS5 Pro should be able to manage 60fps from the GPU side. But the lower the resolution base PS5 renders at the less and less likely it becomes that PS5 Pro will do 60fps from the GPU. And it still also depends if the CPU is good enough for 60fps.
As a upgrade, PS5 Pro is well below the improvement we got from PS4 Pro, especially on the GPU side.
PS4 Pro vs PS4
CPU = 1.3x faster
GPU = 2.3x faster
Memory Bandwidth = 24% increase
PS5 Pro vs PS5
CPU = 1.1x faster
GPU = 1.45x faster
Memory Bandwidth = 28% increase
PS5 Pro is interesting from an architectural point of view in regard to ray tracing, but other than the the specs are boring and well below the upgrade PS4 Pro gave over base PS4.