The post admits that. It clearly says that the impact on users in affected regions was significant but that some regions were barely affected. It would've been nice if they mentioned what regions. But beside that, what's the problem?
" gcloud tells me:
WARNING: The following zones did not respond: us-west2, us-west2-a, southamerica-east1-c, us-west2-b, southamerica-east1, us-east4-b, us-east4, us-east4-a, northamerica-northeast1-c, northamerica-northeast1-b, us-west2-c, southamerica-east1-b, northamerica-northeast1, southamerica-east1-a, northamerica-northeast1-a, us-east4-c. List results may be incomplete.
Luckily for us eu-west1 seems to be working normally."
So the user's outside these zones may have been unaffected, but if this is accurate it is a large number of users affected