This is because on prior releases we didn’t have to know the encoding of strings but in a UNICODE release we need to know the encoding of every item. The binary string could easily be cast to a string if it actually is one with
(value "uuid" of structure "system_information" of smbios) as string
and if not you can make it a hex value
(value "uuid" of structure "system_information" of smbios) as hexadecimal