User blog comment:Nikel23/Announcements for TS4 CAS Demo and gameplay footage/@comment-9930331-20140708194035/@comment-9930331-20140709101108

I think invitations were random. Or maybe cause I have all Sims 2 and Sims 3 on Origin. But then, one of my friends should also got it. Btw, release date is August 12.