Hey there friend. It’s still there, though just not as readily available as it used to be I think. I think numbers have definitely gone down over in Horde side but there’s still some roleplay to be found, you just have to use external tools such as discord servers to know where it is and where to look because the chances of just coming upon it in the game world are pretty slim. The event you’ve encountered is one such gathering that’s advertised in a Horde discord (it takes place every sunday), so it’s all a question of how comfortable and/or willing you are using those tools.
I don’t think tauren roleplay is doing that well since I barely see events or guilds advertised for it (others are free to correct me if I’m wrong) but you can still happen across a good deal of quality characters who know how to portray the race well, it’s just that most of them are scattered across your warband guilds with other races.
It feels like with the most recent patch a good portion of Horde’s community has shifted to playing goblins to ride on the Undermine hype (with a lot of roleplay planned for the place there) but you’ll still find other guilds doing their storylines elsewhere in the world. There’s always some casual RP to be found in Orgrimmar in the Valley of Honor.
If you can take your character to Outland there’s a Kosh’harg event held there (sadly it’s not held in Durotar) and it seems like races other than orcs are welcome to attend.