Is Grief's Threat to Wipe Decryption Key Believable?

[Cerberus]

Analysts Say the Gang Is Escalating Rhetoric to Scare Victims
Regarding the recent tactical innovation by the Grief ransomware gang that is threatening to wipe a victim’s data and decryption key if the victim engages a ransom negotiator, analysts are calling this a desperate ploy to scare a target into paying the ransom demand.

https://www.inforisktoday.co.uk/griefs-threat-to-wipe-decryption-key-believable-a-17556