After the device discovery request, the user receives a set of appliances/devices with a given friendly name. (I believe this information is stored in the Alexa app, although I'd like some clarification on this.)
If a user chooses to rename a friendly name through a third party app, then how are device 'friendly names' updated in the Alexa app? Another question in this forum described this "auto discovery" feature where Alexa constantly invokes the discoveryRequest at certain intervals.
The only method where I've successfully been able to call a device with a new friendly name is by forgetting all my devices and invoking the discovery request.