WWE has fixed what seems to be the final issue with the WWE Network for Xbox 360 users, with WCW and ECW pay-per-views now available.
The pay-per-views are now available under Shows and then Vault. It is very important that under content controls, the setting must be set to allow TV-14 content otherwise nothing will show up.
To change the content controls, go to Xbox Settings, click on Family, and then allow TV-14 content under Content Controls. After you save the settings you will need to restart the WWE app.