I think the next gen will be much longer.
Why? because its getting harder and harder to shrink these chips, which is where most of the performance gain comes from, allowed at a low price.

Ofc there will still be improvements (in architecture), and 5nm and 3nm might be possible... but it ll (progress) be slower than it is now.
plus at 4k, do we really need higher resolutions?

Wouldnt be surprised if PS5 / XB2 is a gen thats upwards of 10years, so its important to get that one right out the gate (ei. ms cant pull any weird stunts like with the orginial xbox one reveal, it has to be on point, and well designed, unless they want a repeat or worse, of this gen, that last longer too).

5nm and 3nm is indeed possible. Why? Because they won't actually be true 5nm or 3nm geometries just like 7nm, 10nm, 11nm, 12nm, 14nm, the numbers are inflated marketing fluff.

But node shrinks are indeed getting more difficult, more capital intensive, more R&D intensive and that is having an effect on how quickly we can shrink chips, although there are ways around it as well that some fabs/manufacturers are exploring.

Did you not read the article? Why did you insert you're own interpretation to the article despite it being cut and dry on what the contents were? SMH.

I think there is very likely that MS and Sony will launch in the same year.  Sony can't risk losing market share if MS launches well before them.  MS can't afford to have their smaller user base made even smaller with people jumping to Sony for the earlier upgrade.  They're both too scared to let the other go first.  I don't think Nintendo gives a shit, as they're really not (or, they don't think they are) in direct competition with those guys anymore.  

3 Years? This can't be correct.
There was a recent thread on this forum saying the PS5 would come out this year

I think 2021 is when the big technological leap becomes affordable.  So, they can launch with something that impresses technically, at a $399 price point.  

Apparently you weren't around for PS3's catastrophic launch failure when it was priced at $600.

People want consoles to be competitively priced, that's why the $600/$500 PS3 didn't sell for shit and that's why the $500 One X isn't selling for shit either.

You want high end hardware in a console? Good luck... Because if history has taught console manufacturers anything - it's that there IS NOT a profitable market for consumers willing to pay $600 (or whatever price it may be) for a 2020 current tech "high end" console.

The Xbox One X didn't sell out on launch day NOR on Black Friday. I don't know how much better you can gauge customer reception than that.

I really can't see ps5 offering a revolutionary gaming experience compared to ps4.
Raytracing could really expand the gaming experience?
Anyway, the longer we wait for a next gen, higher the probability I'm wrong.

That person's prediction was always a joke. We have rumors that a bunch of devs got dev kits earlier this year and just 8-10 months later everyone is going to be ready for a PS5 launch? Nope. The earliest they'll launch is 2019. They may wait for 2020 for the tech to mature. But, there is absolutely no chance that they will wait til 2021.  Especially after announcing PS4 is basically on its last legs in terms of new 1st party support. And the people who jumped in early to this gen are ready to move on. 

TIL  "rather than separating portable gaming from consoles, it’s necessary to continue thinking of [portable gaming] as one method to deliver more gaming experiences and exploring what our customers want from portable. We want to think about many options." means "we are working on a portable console"

Have you considered the above phrase might simply mean "we haven't ruled out releasing another portable some day" and nothing more?