Where's The Tribunal?

It was put out of commission indefinitely because of the fact that it was too slow. There was a huge backlog of reports that was continually piling up and getting worse and worse. Players were getting punished for something they did over 6 months ago that they didn't even remember.

It's like disciplining a dog hours after it pissed on the area rug. The dog simply doesn't have the memory capacity to understand that you're punishing it for pissing on the rug.

I wish they would bring it back for the cases that the system can't really do anything about, like intentional feeders.

Lyte said they were bringing a modified form back to work along side the instant feedback system, and I think there was an Ask Riot about it that mentioned the plan was still alive, but I'm not sure what is happening with it now.

If I had to guess, I'd guess it slipped in priority compared to the new client for a few months. Maybe a 2018 rerelease, but don't count on it.