How is that going to affect phone upgrades? Sounds like WP7 >> WP8 again.
Not at all. This is ONLY about software falling on its face due to an inability to gracefully deal with version NUMBER changes. It's the same issue that was exaggerated to the point of absurdity when some started speculating about why the name was changed to W10 instead of W9 (poorly implemented Java programs that couldn't differ between Windows 95, 98 and 9).
This is NOT at all about incompatibilities with the kernel itself. The article doesn't make it clear what the real issue is nor what the consequences are, which are fairly mundane. If you have the development environment setup and ready to go, then it's a 10 minute fix. Something that wouldn't be necessary if the original developer had been competent.
To be clear, I'm not saying there won't be any kernel level incompatibilities. There may be, but that is not what this is about.
I love WC, and think they generally do a really good job, but technical issues, particularly software related issues, are their weak spot. This is not the type of thing WC is good at writing about.