It’s coming with the official 4.20 release:
On 6/21 I was able to access an example game Action RPG and associated content with it like the Gameplay Abilities page. One example URL for this is Gameplay Abilities in Action RPG | Unreal Engine Documentation. Now, however, I’m getting an access denied error message. Will this be coming back? It seemed very interesting and useful.
Ah awesome, I tried doing a search and couldn’t find a thread, great to know it will be coming back.