I haven't heard of "Bounced Emails" going away... It's a different function than "Undelivered Emails" imo. Example: you can't "delete" an address from the "Undelivered Emails" page. Also, if an address bounced recently, and a script or whatever tries to send another email to that address, the "reason" will change in the "Undelivered Emails" page to indicate it didn't send it due to it being in the recently bounced list.