I too have caused and authored many COEs at Amazon. I have also been involved in 50 to 100 COEs written by other teams and have also observed no instances of this having a negative impact on anyones career. COEs are core to Amazon's learning experience and you can be assigned to write one for simply being unlucky enough to be oncall when the incident occurred.
I've been here for years in a senior capacity and I've never even heard of Simple Workflow. Some products, like Dynamo and Lambda became favorable internally to support the migration to native AWS.
I'm not sure that assigning this to a perceived internal power grab aligns with reality.
This was maybe five years ago. The overarching architecture meme is/was used to say "my technology XYZ is the basis behind these five director level orgs, therefore I should be made the VP of the XYZ project over these five areas."
