What baffles me is that there seems to be no way for either the customer or a data-recovery company to flash a new firmware onto the drive after it has failed. Someone there wanted to spare the few millicents of copper trace for a JTAG port?!
Reputable hosting providers typically don't try to quantify such a loss, but rather outright offer a credit/compensation that is very obviously generous (say, a year or even two of free service).
Especially when a small set of your customerbase is affected, it won't cost you that much, and "overcompensating" like that means that virtually noone is going to criticize you for quantifying it wrong; instead, the public narrative will be centered around "well, shit happens, they did their best and generously compensated".
Edit: who knows it may be related to the HPE issue.
https://www.bleepingcomputer.com/news/hardware/hp-warns-that...