Global services such as STS have regional endpoints, but is it really that common to hit specific endpoint rather than use the default?

Customers in all regions were affected…

Indirectly yes but not directly.

Our only impact was some atlassian tools.

An update to the internal database. It still did not sunk to developers that data has equivalent risk as code. A400 crashed because of an XML file update. I have witnessed my share of critical bugs caused by "innocent? updates to "data" which were treated less seriously because of this. Management and devs alike should change their conception about this.