Sorry for my French, but Who The F&$& has been talking about using separated CPU and GPU?

That is the most stupid idea ever. If a big APU is expensive, it is still far cheaper than discreet components. The simple fact that you have to wire and encapsulate two different types of chips would add extra costs, without considering how to place them on the motherboard and m race memory banks.

The whole point of having a console insted of a PC is the extra power you can get at a lower price, smaller size and more efficient overall design.

Sony, Microsoft and Nintendo will aways use proven technologies and architectures. 

I won't rule out Sony launching a PS Pro 2 this year and it can even be a beast that would smash the Xbox One X, but if they do, it will be using old tech like Polaris and Scavator. 

An upgraded Pro model or just the new Pro model. Either would work for late 2018. Not PS5 though. That would have to wait until late 2019 at the earliest.

The more talk I hear about PS4 and it's momentum and not wanting to take a risk with a PS5 anytime soon, the more I think another upgrade makes more and more sense. Pro having Polaris with some Vega baked in, I could see an upgraded Pro having Vega with some Navi baked in. I don't see a 14nm or 7nm APU happening by late 2018 however, so a separate CPU and GPU may be their only option if they don't want to wait.

PS5 this year is fake.

PS4 ProPro doesn't make sense as most games don't take advantage of even the original Pro.

2018 was just speculation from the author but we always hear about devkits like 16months in advance

https://www.tweaktown.com/news/57845/playstation-5-feature-full-discrete-gpu-apu/index.html 

This is just one link. The rumor lit up a lot of the message boards I go to around E3 last year. I'm not saying they should do this, but it is the only way I can see them getting next gen worthy CPU+GPU combo by next year. I think if they want to stick to APU's, then PS4 Premium should come on 7nm in 2019, and PS5 should wait until 7nm+ in 2021.

It's just a clickbait article. Leeks would be abundant for a 2018 release date – production would have to start in a couple of months, and AMD would brag about it.
Engines are very scalable so they can give a not perfect developers kit, and release the console 2 years later giving developers a sense of technologies to come in the final product.

I doubt they will go full on "discrete chips" like in PS3, but I expect them to use several CPU/GPU modules on a single package/under a single heatspreader, like AMD does with their EPYC line up of server CPUs. Rumors have been going strong for years that Navi will not be  a "single big chip" design, but a modular approach with several smaller modules connected by "infinite fabric" (ultra high bandwith connection), that "act" like a single chip. This has the advantage that the smaller modules reach far higher yields than big chips, so this design should be cheaper to manufacture if the "infinite fabric" itself isn't too costly.

I could see a 2019 PS5 using 2 Zen CPU modules with 4cores+HT each and maybe 4 Navi modules with 18CUs (=1152 shaders) @ 1100MHz each for 10TF FP32 theoretical performance.

Is this different to the other thread?

Infinite Fabric may very well play a part in the PS5. There are so many technologies they can use, and that is what makes the next gen so exciting.

But, Man Alive, a 10TF GPU. I am hoping the baseline PS5 is closer to 20TF. PS5 should be a generational leap over PS4, not just a PS4 revision.