I believe Sony have played their hand perfectly with the PS4pro. What I think they did was force Microsoft's hand so they had to react much sooner than they wanted. Sony carefully 'under-promoted' the Pro to make sure only those in the know would rush out to buy one initially, knowing full well that MS would seize upon this and heavily promote the Scorpio, cementing it in the minds of a much larger audience. 

But why would they do that? I've always said that Sony play chess while Microsoft play poker, and this is a perfect example. There HAS to be a cooling off period between the release of a mid gen upgrade and the release of a brand new generation, otherwise a lot of people will feel slighted. Given that Sony have cleverly positioned the Pro as an upgrade while Microsoft have pushed the Scorpio as a huge leap over the Pro, Sony are sitting in a less vulnerable position, rather like Nintendo has, which has clearly worked for them. It's a slightly different scenario but I haven't seen many people complaining that they bought the Wiiu for certain games only to have those games held back and release on the Switch to give it sales merit. Why? Because they cut and ran, which was the perfect thing to do. Enough time had past for people to forget and move on. This of course meant Nintendo had to be VERY confident in their new console. They obviously had the right to feel that confident. Just look at the sales.

This leaves Sony in prime position with plenty of wiggle room concerning Microsoft's inevitable next gen console. There is no way Microsoft can release a next gen console only one year and six months after the Scorpio, unless they're willing to risk a huge backlash from a lot of their fans. However, Sony CAN risk releasing another console two and a half years after the Pro. They'll certainly get some backlash but nothing like Microsoft. This is why I feel Sony will bring the launch day forward and give themselves as long as they can to gain a substantial lead before Microsoft actually launch their next console. 

IF Sony can offer 4K at 60fps on every single forward conpatible game and the majority of exclusive PS5 games then the 'power' agrument is almost impossible to express to the average Joe. Right now it's a simple matter of promoting measurable and visible differences because stepping up from 30fps to 60fps and 1080p to 4K (the games that will be used to promote both consoles, MS having the advantage here) is much easier to promote to the masses. I am absolutely certain that next gen consoles will NOT be promoted with 8K and 120fps so that leaves NO metric to differentiate other than subtle things that are very difficult to express in screenshots or videos. So therefore next gen will be fought even footedly, leaving Sony with the advantage of releasing first. 

It's not Sony who offers the 4k 60fps. It's still the game developer how he utilizes the resources.

Yep. Sony are promoting the Pro as a mid gen upgrade. It's MS that are leaning on the 4K/60fps promotions. That's my point. Sony can afford to gain a 1 year lead if they wish.

Early 2019? Unlikely. Late 2019? Possibly...

I think early to mid. Sony will want to get as much as a lead as possible. MS can't risk releasing too early and like I said, Sony have more wiggle room here.

Really depends on if Last of Us 2 and Death Stranding are going to be multiplat on launch of the PS5

Highly doubt it. The PS4 jump over the PS3 disappointed initially and wasn't fully appreciated for years. The Pro also disappointed many. Contrary to the current rhetoric, generations need to get *longer* NOT shorter.

I personally anticipate the PS5 in 2021. 2020 at the absolute earliest.   I don't think Sony is concerned with the next Xbox because Microsoft's posturing leaves considerable doubt there will even BE another Xbox after the One line.

Sony isn't going to rush out the gate to get the drop on Xbox. No sense in taking the risk.

I also think, as Angry has touched upon above, that TLOU2 will be a launch title for the PS5. Also available on the current gen too of course. 

I dont see why would they release PS5 in early 2019. Holiday 2019. is definitely posible.

I see no risk here. As long as it's backward compatible and ALL of the earlier game are also available for the PS4 (with less bells and whistles), then no one is going to feel that slighted. With a 6 months to a year lead over the XB4, Sony can afford to simply allow cross gen games to push early sales and with games like TLOU2, which I think will definitely be a launch title, they can ease into a substantial lead.