I personally believe that most PS6 games will be using ReSTIR GI... not even PT. ReSTIR GI can get you close to RT, while costing significantly less. Costs only about 30% the rays PT would otherwise cost.
ReSTIR GI has already been expanded to support PT years ago and is now fully implemented by Nvidia as ReSTIR PT within UE 5. It runs at 1 spp, so the ray count is as low as ReSTIR GI. Unless CDPR plans to create their own version of ReSTIR PT, they are likely to use Nvidia's branch. Or... may be they will put together their own version for cross vendor support.
I don't think any game uses it yet (may be RE: requiem, but I'm not sure), but it seems to be production ready for a while and what Nvidia uses in all their PT demos.
That has since evolved further into techniques like Area ReSTIR, ReSTIR with MCMC mutations, ReSTIR with forward splatting, path guided ReSTIR (or RESTIR PG) etc., all to push the output quality much further while keeping the ray count low. They are a bit heavier than ReSTIR PT, but the quality goes up significantly that you may even be able to go below 1 spp to squeeze out more performance.
With AI denoising and a neural radiance cache, PT should be viable next gen, for quality or balanced mode at 1080p base resolution, if not performance mode. By mid to late next gen, I fully expect PT to become mainstream and may be even hit 60 fps.
What I'm hoping to see is quality mode becoming 48 fps instead of 30 (with 30 fallback only for TVs that don't support it), which would be a major forward-looking change in paradigm.