The IsEmoting property of the player class in the @minecraft/server api returns false whether or not I am emoting.

I tested this on api versions 1.10 and 1.11 beta in a singleplayer world.

Here is some example code (or attached .js file):
import

{ system, world }

from "@minecraft/server"

async function testIfEmoting() {
  let players = world.getAllPlayers();
  players.forEach((player, i) =>

{     console.log(player.isEmoting);   }

)
}

system.runInterval(testIfEmoting, 10);

Jira messed it up a little bit but you get the jist.
Despite using several emotes (like wave and hammer time), the console logged nothing but false.

 

Update: Still broken as of Preview 1.21.0.24