I don't know about that. It was more like common knowledge that one availability zone in us-east-1 was a problem - you would have to figure out which one it was usually by spinning up instances in all 4 zones (now 6)... and that it was the largest of all regions making it ideal place to put your service if you wanted to be close to other vendors/partners in AWS...

us-east-1 seems to be AWS’s not so well kept little dark secret!

In all seriousness though - even non-regional AWS services seem to have ties to us-east-1 as evidenced by the recent outages. So you might be impacted even if it looks like (on paper at least) you’re not using any services tied to that region.

Unfortunately, the fact that us-east-1 is roughly 10% cheaper than other regions usually overrides any other concerns