TBF, we got a hint of Yrel during Shadowlands;
https://www.wowhead.com/news/battle-...nd-yrel-322224
Nothing earth-shattering, but interesting nonetheless.
Actually there was the empty keg quest in Vanilla (which assured that Chen and Pandaria were canon in WoW), the Pandaren Brewmaster class in the WoW TTRPG which was canon at the time and expanded the lore, and the Pandaren Monk pet that we got in WotLK which pretty much led to the class a few expansions later.And for what it's worth, Chen has had exactly nothing in extra lore between WC3 TFT and MoP. If they want to use ETC for anything, they will simply create that lore.
Murmur never appearing in anything other than Draenor content is a relevant argument. The ETC not matching up with Murmur (or any other content) on any level because it lacks a lore basis is a relevant argument. Yrel being a popular character, a new type of enemy (light-based), and opening the door to new possible races is also a relevant argument.You're not giving any relevant arguments for why your idea is better. You just assert it is and refuse to entertain the notion that you could just be wrong. Your personal opinion is not a relevant data point.