There was no need to do more with the Pro, though.  While MS has a completely different GPU in it, Sony took the GPU they already had and doubled it.  It allowed them to more than double the performance for a cheaper price, meaning they are most likely making more on the Pro than MS is making on the X.  Selling more of them, too. Remember, these are just mid-gen upgrades.  There job is really just to provide an option for early adopters who wanted a more powerful PS4/XBO, but will most likely move on to next gen much sooner than most.  So, they will be relevant for far less time than the OG systems, and sell a lot less. 

If the PS5 is B/C with the PS4, than the Pro pretty much becomes obsolete, as I'm sure it will offer the same upgrades and will probably be only $100 or so more than the Pro.  The OG PS4 will continue to sell to people with less disposable income, since it will be $200-$250 less than the PS5 and will still receive cross-gen games for the first year or two.  In other words, there wasn't really any reason too spend so much money on R&D and the chipset, if it was just going to sell to a small subset of people for 3-4 years.  MS only did so to have the crown of most powerful system, which really didn't improve their position.

I agree with your prediction of 16GB, not 32GB, and Sony aiming for $399.  However, I see very little chance of them putting in a 4TB HDD.  Sony is going to be spending a bunch of money on the other internals (Zen+/2, new Navi tech, 16 GDDR6 + (possibly) 4 GB DDR4 for the OS, maybe better cooling solution), I think they are going to try cutting costs where they can.  I think 2TB is more likely.  Hell, I wouldn't be surprised to see them try to get away with just 1TB, at least in the beginning.

Outside of the memory (which I suspect will be 20GB total with 4 of LPDDR4 reserved for the OS ~ this is a big deal), I believe most of that (and as I noted: at least a 2TB HDD [not an SSD], Zen 2, Navi, 8-core proc @ around 3GHz). Should be a comfy fit for $399 as well. Not sure about that release date, but the timing of the purported revelation makes sense and would explain their plans to skip E3.

It's fake, you can't do 880GB/s of memory bandwidth (or you can but not in a cost-effective way). The TF number is also likely to high.

Honestly, talking up 4TB 2.5 inch HDDs is just as ridiculous as talking up 1TB SSDs.

No, it isn't.

Right now on amazon the cheapest 4TB HDD there is $118.

Doesn't matter. This is mainly about storage and such a hit is nothing like what you'd see from a GPU or RAM. Plus, the option to upgrade later on will also be present. 2TB HDDs (which are dirt cheap) in both machines at launch isn't unrealistic.

The Cheapest 1TB SSD is $108.

Irrelevant. SSDs cost more and will yield less storage in the long run for comparable prices.

So what I am saying stands.

Stand by it, as I will do the same.

If you consider that OEM pricing will be significantly lower than retail pricing then it will cost them about the same or less in 2020 for a 1TB SSD as it would cost them for a 4TB HDD.

Again, irrelevant. Getting an SSD will simply be about speed, but you want more storage as we head towards a stricter digital future. A 2TB HDD is the the most likely option with 4TB (since you and others are hung up on the ceiling I predicted) being the highest case (this should have been obvious, but alas, here we are).

And with regards to the rest of the tech in the system its really not that complicated.

No one claimed it was and I have always said it is a fairly easy concept to grasp.

Be it 16GB or 20GB of available RAM the issue remains... a 2.5 inch sata drive that will peak at around 150MB/s (and actually less in the real world) is just going to be to slow. Look at the load times now with 5GB systems then imagine how they will be with at least 3 times more RAM. They are going to have to do something about that or not we will be seeing games with like 4 minute plus loading screens.

16GB of G6 won't be an issue. That plus 4GB of LPDDR4 isn't an unrealistic scenario.

Only two ways to do that. SSD or HDD + embedded nand flash cache. So basically which ever solution is cheaper and less complicated to implement.

As for RAM, again this is simple. As of 2017 the price of 1GB of GDDR5 was $23 and 1GB of GDDR6 was $26. Again not OEM pricing. The main takeaway here isn't the cost but how similar the prices are; basically GDDR6 ram will cost around 10-20% more than whatever GDDR5 would have cost. At this point its a matter of if they are going for 8 chips of GDDR6 (ala PS4) or 12 chips (XB1X) resulting in 16GB or 24GB respectively. When you lok at it that way it doesn't sound s crazy anymore does it? 32GB is and was always crazy though.

When I look at RAM, it will always be crazy to expect more than you should. All else is largely moot.

 My take.

I think the one place they would skimp especially at the start would be the HDD.  It can always be upgraded either by the user or by them when the system parts become cheaper down the road.  You can always delete games and install others.  It's one thing that doesn't give them an edge in power and very few people will call a deal breaker so it makes the most sense to skimp there.  I only ask that they make it easy to swap out so those of us that want more room can throw something UUUUUGE in there.

GDDR5 ram is pretty much impossible. That will ensure a bandwidth bottleneck right out the gate.

SSD isn't really needed with consoles. They boot up fast enough from regular harddrives. A PC on the other hand can take forever to boot up. 

 Off topic, about the amount of RAM, which seems to be an hot topic, I feel that Sony are not gonna be so stingy, as going from gen to gen, the increase of RAM was always very generous.  From PS3 to PS4 the increase was 16X : can we expect a 2X only from PS4 to PS5 ?   I myself said 16GB for a base model, but I wouldn't be surprised if Sony opt for more RAM in the end.