Yes, I may confirm that it works.
As Christopher said in the article, it's possible to set different notification types for different error Classes/Types etc.
More details about the device classification: read the manual or
odmget CuAt

There are also several included variables for errnotify class: $1, $2... $9.
I don't remember their values, it's easy to check: include all of them in the message body and you will see all of them.

When combined with mail box alerts and/or monitoring tools, it's the best way to see all HW-realted issues online.
Want to set the same for VIOS?
oem_setup_env
and do the same.
​

One more example: https://aixportal.ru/forums/topic/mkboot_chrp-error-on-object-data-manager-routine-odm_get_first/#post-1074
Alerts for Missed PV.

The text is in Russian (it's the Russian-speaking AIX Portal), but the script is in the technical language. :)