One SEO professional asked John Mueller during an Ask Googlebot session about algorithm updates.
They asked: Do algorithm updates roll out globally or individually across countries or languages?
John answered: As someone in a tiny country, I like that question.
He would love to have a simple yes or no answer here, but the reality is much more complex. In general, Google aims to make their algorithms as globally valid as possible.
Not having to make variations for countries and languages makes them easier to test and maintain.
But sometimes, Google does have to pick a country or language to focus on first. This allows their engineers to fine tune the algorithms.
In these cases, Google tries to start with a language or country that’s most relevant to the algorithm. That can be English, but not always. When relevant, Google does mention this in their announcements also.
Then, once they find that the algorithm is working as expected, over time, it’s usually expanded to other countries or languages.
So, in short, while Google tries to make everything as global as possible, the rollout of bigger changes can vary.