LOL the Fable thing is actually pretty funny.
The huge timeframe post-Halo5 leads me to suspect they are planning Halo Infinite or whatever (Halo 6) as a launch title. I don't think it's as strong as it was in the H2-H4 days, but still a pretty solid title in regards to marketing/sales.
I can see Xbox doing better than Gen8 in their major markets if they keep sane. Power is a factor but far from the only factor. See : Switch. Most (or at least a great many) people own phones stronger than Switch, but Switch sells boatloads.
Price is severely underrated, as is momentum. And they carry into each other. Xbox brand had immense momentum in the US with Gen7. However, the focus on non-core-gaming and the better than expected Kinect second wind for 360 taught them the wrong lesson opening Gen8. It didn't outright murder their advantage in the US for holidays 2013 either, which in retrospect might have been even worse. The core Xbox superfans bought millions of them in Nov and Dec 2013, despite the higher price and weaker console. Then 2014 came and the bottom fell out. I think the Titanfall month sealed Mattrick's fate and ensured the course correction. Discount, free highly anticipated epic marketed game packed in, and lost the month. It was a bit of a slap in the face to those that bought the day 1 models ($499, no game to $449 and $60 game a few months later). And still not affordable enough to turn the general public.
I do think Sony is missing the boat a bit with regards to Gen8. The insistence on staying at $299 is not ideal. I think at most today the Slim should have some bundled titles (rotate historic 1st party as a freebie, UCC, UC4, TLOUHD, etc), and be $249 with random $199 specials. I actually think $199 slim/$349 Pro would be correct. Pro/X are niche, people willing to spend more purely for power are rare, and not as important to worry over due to it naturally overlapping with those people simply willing to spend a bit more for a WAY better PC.
But $199 is a gigantic advantage that could lead to a few million more buying in.
In Gen7 'ecosystem' was pretty much non-existent in modern terms. 360/PS3 games, Gold and Plus didn't carry over to Gen8. This time around, all of it will carry over. And that means something. If people have libraries that they enjoy, and ongoing subs (as well as some being a part of a particular online community such as Overwatch, Destiny 2, whatever), it absolutely will make it more likely that they stay within either Xbox or PS environment with their next console purchase.
I do think the largest individual indicator of 9th gen success will be : what is the best console at the most reasonable price. Globally I don't see much a chance for Xbox to be competitive. But their target markets of NA+UK are fairly sizable. Anything north of a 60M gen for them is a big win imho. Less than 50m is a disappointment. Less than 40m is disastrous.
