Digital foundry also took notice , and of course SONY also has some talented engineer on their side who also notice this problem.  

You might be right, but you also need to remember we are talking about AMD GPU here, not Nvidia , 15 teraflop Nvidia will be equal to 20 to 22 teraflop on AMD gpu , and also if PS5 releasing in 2020 or even 2021 , 20 teraflop + will be a mainstream GPU or standard even on PC. And high end will be like 24 to 30 teraflop on AMD PC GPU.

its so early, and even further away. kind of curious if they might decide to step it up and not give xbox a year head start. time will tell. I will be out at midnight waiting on both at launch anyways.

Hahaha...oh dear, who ever wrote that article is complete idiot.
Customized GPU based on Navi for PS5...sure.
Whole Navi architecture just cause of PS5...oh dear, is this guy for real?

if Xbox One X can have 12 GB GDDR5  on this gen why not go nuts on next gen. Also future PC GPU will also go nuts. Even AMD has GPU that support 64 GB HBM2. And also even if it's imposible "a man can dream " . XD 

That is semantics.

The article and some followups touch the fact that AMD can´t compete with Nvidia on the high-end spectrum, with the disappointing performance of Vega. So, Navi was designed from the ground-up to target console environment.

In a previous thread, I said it was ridiculous to imagine the PS5 being released with an "unproven" GPU architecture. However, this article shed some light on what Navi really is. 

According to the article, Navi might be a revision on the RX500 series and still a GCN. AMD is probably hoping to use the same base to Xbox Next and even a new Nintendo semi-portable console.

If Navi could be scaled down from console level to mobile level, it would be a big win for AMD. 

I still believe it could be too much of a risk for Sony. Sony position now is weaker than it was during the PS2/PS3 transition. But at the same time, it is comfortable enough for not to rush into a technological arms race with Microsoft.

Yeah , i understand cost is the problem here, but PS4 also first came with 8 GB GDDR5 when most  of High end PC GPU are 6 to 4 GB GDDR5 in 2013. And still they are managed to make a a high margin profit each of consoles sales. 

That's why it depend on how far mainstream GPU will evolve  in 2019.  It's possible for ram price goes down  in near future  or new tech are helping make the price of ram a bit lower  (like HBM3 rumored to have lower cost production ) will help shaping future consoles. My prediction are merely based on mainstream GPU that are existed today and possibly coming near future. I might be wrong thou.  

I predicted between 12-24GB of RAM, because of prices as you mention we might actually just get 12GB. But don't we need 24GB ram as minimun for next-gen graphics? I read that from other people in resetera forum that it's required for better textures, more polygons and lightning effects.

Man, if this is true that Sony has Navi, while MS gets stuck with Vega, I'd imagine that we're going to be seeing an exact repeat of this gen, including the power difference between the OG consoles in GPU power, with the same Zen CPUs. Not looking good for Xbox.