Like many remote databases, the manufacturer doesn't add the devices, they just make sure the codes are good. It's users who add the codes, so you can teach the codes to it, so you can use them in your system.
Make sure to name the commands the same as they are on the remote- one of the biggest PITA issues with codes is incorrect names, which results in other people adding codes for the same command with a new name. Then, when someone comes along later to set up their remote, they won't see the command they need, which adds confusion.
If Oppo is smart, they'll use the same command set for all DVD or CD players (each type with their own set). That way, people don't need to wade through 50 code sets for a DVD player. Since most good remote RF receivers/extenders are able to assign output jacks, having two source players in one system with one code set isn't a problem.