It was there prior to 8.1.5 but the size of the file is operating system dependent.
For 32 bit OS it is 2G
For 64 bit OS it is unlimited.
This is from Oracle documentation
Export reaches the value you have specified for the maximum FILESIZE, Export stops writing to the current file, opens another export file with the next name
specified by the parameter FILE and continues until complete or the maximum value of FILESIZE is again reached. If you do not specify sufficient export filenames to complete the export, Export will prompt you to provide additional filenames.