I have >50 MSA on Customer Sites and never made a Shutdown Script for Power Fail on the MSA.
The great problem is, what if the MSA goes Down before the last Server?
Than you have a realy Data Corruption.
Maybe you start the Shutdown on Exchange Server and than on MSA. Now the Exchange need 10min. to Power down and the MSA only 2min. While the Exchange DB is going down, the Storage access fails. > Bang
You have to check if all Servers are realy Power Off, Ping may be good, but for Database Servers it is not sure.
From the Manual:
During a power loss or array controller failure, data stored in cache is saved off to non-volatile memory (CompactFlash).
The data is then written to disk after the issue is corrected. To protect against writing incomplete data to disk, the image
stored on the CompactFlash is verified before committing to disk.