Keep in mind that the problem isn't having Windows build and run on an Arm chip - they already have that - but having all existing programs keep working as they did on the new chip without any perceived loss of functionality and performance.
And aside from Microsoft, i do not see Intel and AMD to stay still and go "oh well, it was nice while it lasted".
IMO of everything mentioned in the article, the most realistic option is for Microsoft to have the next Xbox use ARM chips instead of x86 as they'll have little existing backwards compatibility concerns (and can always benefit by selling existing games again for a new console :-P).
It's worth remembering that Dave Cutler was in charge of that transition. He's widely viewed as one of their best.
If Microsoft had a high profile project, until he retired, Dave was the go to guy to lead it.
Surely not relevant to the vast majority of consumers.
Developers and businesses may have old executables they still use. But those users can buy Intel based PCs.
But the music stops when the isa is completely different