I believe this has been suggested before. It's not a bad idea. Although we have at least 1 weekly hosted GM events. And these are not always 1 vs 1 tournies.
They also consist of Tag team tournaments. Some original events like 1-hit ko event, dodgeball, village war, labyrinth and so on. We like to keep a certain variation of events so they don't become monotonous and boring.
Sometimes these events are made randomly on a day. Sometimes I post the day and time of the event on forums. So stay updated