I agree with ALITHEGRET. PC market has no competition in the OS market. It's Microsoft that needs genuine competition.
Also, neither extremes are true regarding Intel vs ARM for Windows PCs.
-Let's say even if Intel dies off tomorrow, it'll take decades for ARM to take over the PC market. What this announcement will allow is have Intel not take off its foot off the pedal regarding low-power PCs.
Also, they do have chips for the cheap 2-in-1s. Well, Tablets too. The Apollo Lake platform is used in few Tablets and its basically a value 2-in-1 platform. What they don't have is even lower power than that.
-If Intel does nothing though, they can be noticeably threatened.
Emulators have their limits. Even among Windows versions, compatibility issues exist that don't get fully addressed until years after the release. An entirely new instruction set will be worse. Intel will be fine as long as they don't completely ignore it.