The answer is yes, they should be tested! The only consideration to take in this instance, is that companies do not want their servers shut down due to possible damage and prolonged times for restarting their IT network. The decision to test these items lies with the duty holder. They decide to reschedule testing when maintenance is scheduled, to avoid unnecessary interruption.
The IET 5th Edition Code of Practice offers guidance on testing 'Equipment Racks and Bays'.