From what i see on the site, i don't see a lot of chat room chatters spending time in this room. There's the Testimony forums already as well. The YouEdify thread could easily be used as a testimony room i would think, as its not used often otherwise, that i know of.
I don't know, people come up with all these room ideas, but the rooms we have aren't really used much. The Lounge is you're looking for brainless chatter, the Bible Study if you're looking for something more spiritual. Rest of the rooms are only occasionally used, and often not for their intents. I just can't see adding another room, personally.