To be honest given they stated they planned to keep forwards/backwards compatibility with the current Xbox One models seemingly for at least the first round of new games I did wonder what the benefits were of refreshing the low end when going from past generations the existing models are likely to continue to sell as an intro system for a good few years into the "next gen" even without that cross-compatibility, most users probably wouldn't see or appreciate the CPU bump for a while at least. I guess the fact that Sony seem to be taking the same high-end exclusive route also removes the chance of them having to compete with new hardware in the budget sector anyway, while XboneX was arguably Microsofts strongest launch this gen and seems to have been taken as an indication from the companies that people are now willing to buy ~£500 full systems again.
I know a lot of people think PC gaming is getting too premium at the moment, but to be honest I think gaming in general is just becoming such a mainstream hobby that people are willing to invest more money into it, and companies will take any opportunity in any market to capitalise on that shift first, guaranteeing higher margins at the most cost sensitive period, while focussing on the raw market-share potential of more traditional price points second(I don't think the budget gaming market will disappear in PC or console but it does seem to have ceded space & focus to smartphone gaming, particularly outside of Europe).