Traditionally, there is no such thing as a hostname for a Symmetrix array as it is classically a fibre channel array with no ethernet or IP interfaces.
OCI uses the serial number of the Symmetrix array as the "name" within OCI because it is guaranteed to be unique, but more importantly, is what is used via symcli commands, which is traditionally the management interface of the Symm.
Some storages arrays support nicknames, or labels. OCI doesn't currently retrieve the label or nickname of the Symmetrix array.
Some customers that know their SYM arrays by assigned names create a custom annotation on the Storage Array object in OCI and populate it with the array's assigned name. You might call that annotation "alias". Appropriate strategies for maintaining that annotation data will vary depending on environment size, rate of array lifecycle replacement, and available sources of data about which serial number corresponds to which vanity name.