This whole iterative direction seems terrible. Adding additional optimization work to devs, with foundation geared towards the lowest platform. Devs will have to be mindful that the 4-7 year cycle (which 4 nowadays can be short on the developer end) is now more around 3 to where they may have to shift work mid development to accommodate the possibility of a new iteration releasing.
On Microsoft's end, we have R&D costs split between two platforms, with the higher cost and likely more attractive system releasing less than a year to just over a year later. All while migrating the core attractions of these platforms to Window PCs, where likely those that the Scorpio would attract would already be invested into. Sony could end up doing similar steps. While these are more their concern, and have employed folks who look into these very things and get paid more than I ever expect to be, it still seems a major risk in a world where people are more focused on the all-in-one devices they carry with them always than set boxes.
Then you have to consider how the company's may escalate/accelerate the process in attempts to remain competitive.
From a competitive/business standpoint this makes sense, despite the risks. But as a consumer it's a mess.