The Post Future's End books take place in comics continuity not animation continuity and the comics continuity in question is the the New 52 continuity. The event was literally called NEW 52 FUTURES END. It being an alternate future doesn't change the continuity it is set in. It branches from the New 52 continuity and they're still publishing it so New 52 hasn't been abandoned which is what this was all about. They've still maintained Red Hood and the Outlaws brand as well.