From a commercial perspective, there are always first-movers. The kind of people who, no matter what, must have the scorpio in the launch timeframe. But unless there is a distinctive firstparty game for the scorpio, just like the Zelda game for Switch, then it is just a powerfull hardware box, with no real value to gaming consumers as I see it. But lets see what they will present at E3 for the launch.
Microsoft must assume that Xbox 360 owners (who are still out there and havent migrated to the current gen), will religiously migrate to Scorpio. But why should they?

Late adopters have a higher chance of buying a console that has the best deal. They wouldn't have stayed on the 360 this long if they cared about the graphics.  The adopters of the scorpio will be in the minority as is any premium product. This gen is half way over and the baseline Xbox One will gather the majority of the sales. The Scorpio has a higher chance of being adopted by people who already have Xbox Ones or tech enthusiasts who have the money to spare.

He's kind of right. When Sony times the PS5 launch it should be safe for 4k gaming to drop. Microsoft jumped the gun on 4k gaming big time. They are just doing this to one up Sony. Sony didnt make the PS4 4k capable because they didnt believe the market was ready nor that the hardware was cost effective at this time. People are streaming more, but sony only screwed up by buying gaikai for BC streaming. You're hyping up a console thats only going to be purchased by a minority of people while company its not even headlining for is losing badly. When sony drops more games its kind of over. Xbox gamers did the same thing during the OG Xbox and Microsoft had to cut the gen short because they were decimated.

i still cant see this being a good deal for xbox one owners. its like you have to buy a new console just to have better multi-plats. anyways i dont see this selling more than xbox one it will trickle along just like the ps4 pro does

Microsoft knows that multiplats are where the majority of the console sellers come from but the marketing deals have already been set by sales and the majority of the people wont even make use of the scoprio. Its also an admission from Microsoft that their exclusives wont do muchfor the platform because they will be few and far between since the third party wont be there to create the exclusives for them. They need to be more like Sony who made their exclusives look better than their multiplats when they had the worst running multiplats. 

And everyone was surprised.

Now if they hit a $399 price-point, that would be surprising, and make Scorpio an incredible value purchase.

I'd be surprised if it was under $499. 

Erm no and far beyond being right. If you havnt notice 4k has already hit off. The Scorpio would have been planned years ago not as a last minute decision. MS had another console that was due last year which is more like the PS4 Pro which they scrapped due to it being a silly idea going half way with specs. MS is a PC company which houses heaps of 4k content. They know whats going on.

As for thinking this is to only 1 up Sony.. thats the problem with this industry and its fans. ALL companies are trying to 1 up each other, not just MS. These consoles take years of planning and reserach. There not just  (lets quickly rush a system to be more powerful).

MS most likely dont care what Sony do. There aiming for the 4k market something the PS4 Pro failed to do.

I tend to agree on those assumptions. Basically not that many of the Xbox one consumer base, would buy the Scorpio, I assume. I believe they have a bigger tendency towards adopting the PS4/Pro then.

For who? I agree, that a price point of 399$ is the sweetspot for launch. But why not buy the Ps4 pro then. We should assume that the PS4 pro will drop in price by holidays, and the PS ecosystem of games is just far richer and diversified than one the Xbox platform.