No that is not correct. You have been able to restore from a network share as far back as SQL 7 (and probably further back). The UI (Enterprise Manager and Management Studio) will only show you the local drives on the SQL Server. However if you use the RESTORE DATABASE command you can specify a file on a network share to use for the restore.
RESTORE DATABASE MyDatabase FROM DISK='\\Server\Share\Folder\MyDatabase.bak'