Ironically, the Quartet is quite controversial in Tunisia (I'm Tunisian), some sees it a businessmen-controlled organization that is steering the political scene in Tunisia, while others see it as a left-controlled organization that is doing the same. All in all, a lot of people were not happy with these organizations mingling with the politics of the country.
So I would say, this news came as a big surprise to us. Sarcastic comments has been popping all around on social media since the announcement.