Hmm that’s not true, nowadays most new things will start with small regions, typically us-east-2

That's a repeated wrong assumption. In general there is no unified rollout plan within AWS. Each service can use a different method.

I think it has more to do with the fact that it’s the oldest region, and they support some odd things there that do not exist in other regions.

Do you really believe that the biggest region is used for testing?

Not true at all