What the article is missing is how they learned the new error messages are now more helpful to the end user. Some kind of metrics: maybe, the number of support

What the article is missing is how they learned the new error messages are now more helpful to the end user. Some kind of metrics: maybe, the number of support tickets/angry reviews decreased? Otherwise without clear criteria for success I'm not sure if it was worth it and wasn't just changing the error messages for the sake of changing. Sure what they talk about makes sense but "it makes sense" is not a business metric.