Remember Me had it before then–a custom addition to UE3 since UE4 wasn’t available at the time. I wouldn’t be surprised if something had it before then too.
Support for PBR is similar to how VFX started doing things physically based/linear workflow. The hardware is fast enough to support it and it makes things more standardized once people start using the same settings for things which makes the whole process faster and easier. Before, you would just make something and adjust until it looks good, but now you can start with real-world values so you don’t have to make guesses, and once you’ve done something you know how to do it again later.