As discussed here, I and Jugus deemed it unnecessary because it only had a few articles, all of which overlap with all the Sangheili as a whole. So it's better to just use the Sangheili category rather than make one that's too specific.
As for the Unggoy voice clip, yeah it sort of sounds like he says "thalvadamee", but it seems like too much of a guess to deem it so. There isn't any confirmation what it means; the only evidence is that the clip was titled "grunt look_ingme8". Often times the Covenant voice clips are done by just reversing human speech, as is the case with "wort wort wort/go go go". It's going to look odd later on when someone asks where Thel was mentioned in Halo: Reach and the only answer is a brief voice clip that sounds like gibberish. It's a nice find, but maybe it would fit better on a trivia section or elsewhere. Sometimes a tiny bit of speculation can end up causing disaster years later, as shown by "Sharpened Shield" and "750 ships at Reach".
If it helps, I'll try to get in contact with some friends with Reach sound coding (they're the ones who got me the voice clips) and I'll see if they can confirm anything or not. Thanks for being respectful. Tuckerscreator(stalk) 17:49, 30 September 2015 (EDT)