What are your thoughts on Zen+ and Vega 20?

It's not Hyperbole.
Polaris - 2016.
Vega - 2017.
Navi - 2018.
Navi Successor - 2019.
Successor to Navi Successor - 2020.

I doubt 2019 will see the release of the next gen. But even in 2019, Vega will be far from the latest and greatest and far from being an efficient design to other alternatives.
AMD's Fury with HBM for example is only 2 years old and it's performance isn't holding up.

A semi-custom Navi Successor would likely make more sense. Not Vega.

Ryzen is going to be slower, hotter and use more power than Intel.
Ryzen+ (Refined Ryzen) will drop in 2018.
Successor to the Zen architecture should arrive in 2019/2020.

AMD expects to replace AM4 in 3-5 years, depending on the market. (I wan't them to release a high-end chipset and high-end motherboards, so hopefully AM4 is short-lived.)

AMD may release a successor to it's Cat cores, which the next-gen consoles will probably use anyway rather than anything Zen based. (AMD has stated it is working on other CPU Architectures.)

And then we have the Fabrication side of things. Want me to elaborate on that and why 2019 is not likely?

Not enough information on Zen+. But it should be a good refinement, hopefuly AMD takes a unified L3 cache approach with it.
Zen is just to get AMD's foot in the door, a good platform to iterate upon yearly, it will still loose to Intel.

As for Vega. Vega took me by surprise, I didn't expect to see such a large amount of core improvements with AMD's new NCU architecture, I was expecting to see it in Navi.
Thus... Navi should prove to be extremely interesting.

I think you can take the rumour from the tittle. Because it is trivial that if the ps5 exists it will be BC.
It is elementary my dear watson,  there is no Cell to burden us no more.

I got a new rumour for you: the Intel 7th gen CPU will also be backwards compatible. Also the ATI and Nvidia new discrete graphics cards will also. And Dx13 cards will also play dx12 games. Mind blown, am I right.

Galaxy s8 will play galaxy s7 games also, is a epidemic of backwards compatible it seems.

If PS5 is not backward compatible this could be a huge deal-breaker. Obviously going forward all console needs to be backward compatible.

Yes. Hyperbole.  Is Zen and Vega better than what AMD has, now?  Yes.  In just 2 years time they are not going to be considered old and slow.  Slower?  Yes.  Slow? Hell no.  And I'm sure they will be using some improvements that AMD develops along the way, just as the PS4 Pro GPU does.  Using somewhat older tech is just something console gamers are used to, considering these things are launching at just $399.

Also, Navi has been put on hold til 2019.

Edit:  I also know that AMD/GF is switching to 7nm.  I don't see how that refutes a Vega GPU, considering they are supposed to release a Vega made using 7nm in early 2018.

It's plausible that PS5 will use Ryzen. The first apu based on Ryzen,will come sometime this year,and will have 12 compute unit's. It will be a apu geared towards enterprises. So that a apu,with a lot more compute unit's will be ready for PS5 launch is within reach. What other choice would it be,if they stick with using AMD apu's? Besides.i think we can say with absolute certainty that they will be using a x86,so backwards compatibility is pretty much guaranteed. The reason PS4 isn't backwards compatible with PS3,has nothing to do with greed from Sony's part,but because of the architecture of PS3,which is very complex,and based on a very different type of cpu. In some cases,the Cell BE that are used in PS3,beat PS4 in performance.

That is only a Rumor. Untill such a time AMD has confirmed it, we should trust AMD's roadmap to some degree.

Well. That couldn't be anymore obvious.
But just because it's better than what AMD has now, doesn't mean the goalpost won't be shifting over the next several years.

The Playstation 4 is an old GPU design. It was old when it released. Having a few "customizations" didn't dramatically change it's capabilities... And the games speak for themselves.

In 2019/2020, mainstream hardware will not only be more efficient than AMD's first Generation NCU architecture, but also cheaper.

7nm is not going to arrive in early 2018 for large monolithic chips at Global Foundries.
It will arrive in late 2018, early 2019. Which may push next-gen consoles releasing to 2020.
But don't take my word for it: globalfoundries.com/newsroom/press-releases/2016/09/14/globalfoundries-extends-roadmap-to-deliver-industry-s-leading-performance-offering-of-7nm-finfet-technology

2018 RISK production starts in early 2018. Commercial chips come much much much much later.

So no. You will not get Vega in early 2018 built at 7nm.

Heck, Global Foundries has more of a history of cancelling/delaying it's new nodes than actually being on time anyway. So don't be surprised if it blows out to late 2019.
New process improvements are also slowing down and per-transister costs are increasing due to heavier reliance on things like multi-patterning, EUV and other technologies.
Samsung will release it's 4th Generation 14nm process soon (If it hasn't already) which should be fairly competitive for awhile to come.

If 7nm flops at Global Foundries, then they will likely just license Samsungs technology again, Samsungs 10nm process will be a Hybrid process where the BEOL or FEOL is 14nm (Some rumours are saying 20nm).

TSMC's 10nm process should have a density advantage over Samsung with some luck. (Some estimates place it at near Global Foundries 7nm in terms of density.)
And then you come to the conclusion that the fabs naming schemes for process shrinks is bullshit and not comparable.

I doubt the PS5 is even in development considering the pro launched a little while ago.

I was referring to Digital PS1 titles on the store.

The PS5 has no doubt been in development since the PS4 launched.