One thing that gets lost in the tea leaf reading: Spencer continues to hype PLAY ANYWHERE. Which means an XBOX-branded windows handheld will meet his needs just fine. All it needs is an XBOX GUI and (maybe) dual boot into full Windows.
No need to cook up an ultra-low power Lockhart, especially if the next gen XBOX will be a similar hybrid: straight off-the-the shelf parts will do the deed. AMD, INTEL, or (hang on to your hats) QUALCOMM. An easy sell at $499. Maybe $399 with a two year Game Pass contract that will take it into the next gen with a trade-in plan.
MS is now very strong on the PC side and PLAY ANYWHERE is a solid hole card they can play to portray a handheld PC as an XBOX.