The only issue with everything you wrote above is that it's based on the assumption that Tom of MLID is accurate on pricing.
He was wrong on steam machine. Come to think of it, looking at his track record, was there anything he got right on pricing?
But let's assume it's true for a moment. It depends on how they market it. For a console, it maybe too much but if they market it like a PC it could be more reasonable. And like you said, PC is doing well in Asia, so perhaps Xbox as a PC will do better in Asia as well this time.
The question of how they'll handle steam integration is an important one. As everyone wants it but like you said, how exactly are they going to profit if everyone just goes steam?
Anyways, this is still 1.5 years away from release. A lot can happen in that time. Pricing is usually decided and changed very last minute so no point speculating this early.
I personally think Microsoft is more worried about SteamOS than the PS6. Sony isn't trying to replace the PC but what Valve is working on could very well entirely replace windows in the future, not just Xbox.