That's the I love about this type of article: lack of sample size.
I cannot count the number of issues that I've encountered over the years that were portrayed as "bugs" that were anything but.
In the billions of machines out there all sorts of subtle corruptions can and do occur. Those are often revealed, at some point, when an update is applied that begins using a path that had previously been unused. But those sorts of failures are not bugs.
Real bugs will hit a very significant number of users up through all of them. If even 10K machines of the embedded Windows base have some sort of issue, probably very few of which are the same issue, that isn't the result of what should be called a bug. They're idiosyncratic failures tied directly to the machines in question. They happen, they have always happened, they will always happen - and not only under Windows, I might add.
Just as one swallow does not a summer make, one user reporting a problem after an update that seems to be specific to them does not a bug make.