How does the author know this bit?
I've lived on streets that definitely existed in Google maps, but where the exact address definitely didn't exist in USPS address system for like 6 months until they finally updated it, which caused... a very similar same set of issues described in this article. This has happened to me twice.
In my experience at least, USPS doesn't give a shit what Google says or not. Maybe it's changed since then? I would require some serious convincing though.