I got confused reading this because I wasn't sure how I, as a reader with no knowledge of the system under discussion, was supposed to know that all the buckets should be in the same region. Nor is it clear to me how the "for loop" version would handle the case where exceptionally one bucket is different. Which is a more interesting discussion imho, that's the whole point of having it as a configuration field, after…
The example in the article shows a need for cartesian product of (bucket name) and (lifetime policy), with a fixed location. Nothing stops you from defining a separate category for the exceptions, and just append them to the resulting list. Or you may want to assign each bucket its own location, then you define it along side the bucket name.