Who cares? Thal'dranath had litle to no development and there were no concept art of it, only ideas. And it didn't have a lore to back it up unlike Farahlon. And Ion didn't say it was cut completely, it is going to be replaced with something way cooler. To be honest, I'd rather see a troll themed content zone rather than another elven ruin zone with Legion presence (Suramar, Azsuna, Broken Shore all has it -- and partially Val'sharah.)
Honestly, they shouldn't have shown it in the first place. Then the community wouldn't have something to be whiny about.