This is nothing new, but it was openly affirmed (per Zizek at his talk in Toronto). We also now know that "speculative realism" is a term that he is distancing himself from.
Some other quick thoughts:
Three of the four SR originals question SR's very existence as a school of thought, or "speculative realism" as such. In other words, "speculative realism" may be best characterized as a tendency or group of philosophical characteristics (materialism, realism, etc.) rather than a concrete school. Looking at SR as a concrete phenomenon with rigid borders rather than a fluid philosophical tendency may be reducing things down to a single term which ought to resist categorization.
However, I've often thought about whether there is just one idea or concept which would put the four original SR philosophers in the same boat. A "critique of correlationism" would be it, even if someone like Meillassoux ultimately returns to it after deconstructing its history.
As for the offshoots of speculative realism: I've always said that no one in their right mind would refer to their own position as "speculative realist" or call themself a "speculative realist." Analagously, no one openly called themself a "postmodernist" but rather identified with deconstructionism, post-structuralism, etc.
On the other hand, I find it troublesome when one tries to cut a neat divide between the various SR factions strictly along some epistemological/ontological axis. There doesn't appear to be just one neat line that one can draw in order to put SR folks into little boxes, despite there being a multitude of factions. (As an aside: I also find it troublesome when we try to "dictate" who can belong and who can't, to whatever faction, or blankly state "if you believe this then you are that," or state that "this person is part of the conversation, that person isn't." Not true. We're all partners in this dance, like it or not - so this business about allowing others to "be part of" the discussion or conversation or whatever is just bull. Everyone is allowed to "be a part of" the conversation, Zizek included).
It probably can go without saying that my own personal interest is in Meillassoux's divine inexistence. Another philosopher whose perspective I enjoy is Iain Hamilton Grant, and his "neo-vitalism. As well, Brassier's forthcoming naturalism is also something that I enjoy wrestling with. So that's probably why I've been engaging with them lately.