Re-initializing or re-building that RAID is going to blow away any data stored there, so there is not a way to simply re-apply a previous RAID config unfortunately. I personally have never heard of drives falling out of RAID for any reason, certainly not during a power cycle. A power cycle is the only way to fully reboot the CIMC, and we have over the years needed to routinely ask for hard reboots to recover CIMC access for memory leaks as an example. I would suggest hunting down a tech support from recently, prior to this reboot, and pulling a new one now, then I would open a TAC case to see what differences can be found there. But the questions (as I am a TAC engineer) that I would ask would be:
Does the CIMC now show those drives in JBOD?
Have you dropped into WebBIOS for the RAID controller in question?
What does WebBIOS show for those drives?
Where is/was the OS installed prior to this reboot?
That should be a reasonable amount of data to start troubleshooting with. If you do decide to open a ticket, PM your SR number to me.
If you boot some sort of 'OS on a Stick' ISO via vKVM vmedia (that has the correct NIC and storage drivers), then you could likely read the local file systems, assuming your 2 drives are still in independent AHCI mode.