I selected 'Junior Justice League'. But i don't agree with it fully. Ideally they begun as junior justice league. Like Dick Grayson was supposed to be the future Batman. But with time they developed so much on their own that they can't be called junior Justice League. They are Titans and they don't need to be Justice League.
But a Titan joining Justice League is a promotion. In our world they might be an equal and possibly exceed JL. But in DCU, Titans are not in the same level as JL. Ideally, they would become the Justice League taking the original's place while their successors can be Titans or the next generation. I see the future of DCU like this. But in real world the stories are always set in the now. So, they are almost equal to JL.