AMD CPU question for a PowerEdge R6525

Hello,

If I enable PSB (Platform Secure Boot) which vendor locks the CPU to Dell's firmware signing keys, if Dell's keys were to ever get leaked causing the UEFI firmware to become insecure, would Dell rotate the keys to publish new firmware?  If the firmware has new keys, then would the vendor locked CPU's no longer work with the Dell server?  Do these questions make sense?  Thank you