Intentional.

It's more explicit. And it makes future goimports runs faster, not having to scan the "v4" directory to figure out what it means.

Seems inconsistent that it leaves import "google.golang.org/api/sheets/v4" alone.

I don't follow. You didn't say anything about that in your bug report.

I still think it's fine. That is: don't mess with people's existing imports if they wrote them by hand or tweaked them by hand. But if we're adding them automatically, then we get to remind them of convention. (dir name == package name) If they don't follow convention, we help readers out. If they don't like it, they can delete it or follow convention.