This thread is simply about a user-visible warning screen in Chrome. It has nothing to do with apps, etc. And the warning looks like it's skippable, since it has an "Advanced…" option. Not sure how this is supposed to impact dev workflows or be user-hostile in any way.
It does have to do with the overall topic of traffic inspectability.
As explained above, a relatively recent change in Android makes applications not trust user store certificates by default, except if an application explicitly opt into that. ~None of them do, except Chrome.
The solution to that problem was to install the certificate into the system store. But now Chrome considers all system store certificates to be public ones and requires CT for them.
So now there's no way to install a certificate to be able to inspect traffic from both Chrome and other applications at the same time. (If a certificate is in both the system store and in the user store, the system store version takes precedence, so Chrome would still require CT.)
There's a Chromium bug the author of the article filed to document this regression and you can already see a Chromium dev argue that "reverse engineering" (i.e. the ability to inspect the traffic your own device produces) is "understandably" not an addressed scenario: https://bugs.chromium.org/p/chromium/issues/detail?id=132430...
To be clear, this particular change isn't the end of the world, but none of them are since they're just using the slow frog-boiling method. Each change makes it a little bit harder until eventually it won't be possible at all.
