I saw it on a IGN article http://www.ign.com/articles/2013/07/18/whats-after-saints-row-4-for-volition and on some other sites that they're taking a break from Saints Row, I also saw on another site, I can't really remember which one, that this was the last game with this story arc.of course there'l be a saints row #5. deepsilver wouldn't have bought the franchise if they'd only bring out one game. also wtf is up with the title? it's just a blatant lie.
EDIT: http://www.gamespot.com/news/next-saints-row-could-continue-in-a-different-direction-6411118
There you go, I also edited the title.