Backupset with expiry on - how useful is it ?

Hi all,

I used to thought the option "backup will expire on"  is use to define when a backup is deem no longer useful to a backup retention period. But from what I have understood after reading around , it is use to define when a backupset can be overwritten.

q1) if my scheduled backup always backup to a different filename , does that means that this option is not applicable at all ? - since there is no chance that a backup done will overwrite a previous backup ?

q2) if this parameter / option is set, is there any command/method/maintenance plan in SQL server that will scan through the backups done and delete backup that has already pass the expiry date ?

Regards,
Noob