@JB Mene, Thanks for posting in Q&A. In general, before performing retire or unenroll action, we need to back up the Bitlocker Recovery Key.
https://learn.microsoft.com/en-us/mem/intune-service/remote-actions/devices-wipe#windows
Please check if the device record in Microsoft Entra ID is still existing. If yes, we can find the Bitlocker Recovery key under the device record there. If not, unfortunately, once a device is unenrolled from Intune, detailed history and management capabilities are limited. I am afraid it can't be found.
Thanks for your understanding.
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