I've no problem with you creating a chat thread in the interim. Obviously though if what you want to talk about is something specific that may require more than a one line answer, starting a new thread with the proper title is the way to go.
The chatbox is fun to have. But if we've noticed one thing since installing it, its that the number of new threads has fallen rapidly. This has a knock-on effect on amount of time that people who don't use the chatbox spend on the forum (because there's sod all new to read / reply to)