Well if that rumor is to true, the unfinished Cad Bane arc will not be released. There would be 6 to 8 episodes if that is right. I'm hoping for more, but I'm pretty sure I'll be disappointed with any possible outcome. If they were planning on the show running for 3 more seasons, we won't be getting any big wrap up of Darth Maul, Ventress, Mother Talzin, Rex, or what would surely have been the further adventures of Ahsoka. Some of this will hopefully be touched on someday, especially Maul, but I'm sure we won't get the end of everyone's storylines like we would if the show had wrapped up according to it's own timetable.
But I'm still holding out hope for two theories: This rumor isn't true and we will get basically almost all of season 6. Or perhaps the Disney animators (now that the Lucasfilm animators have been disbanded) will complete the series properly beyond what was completed of season 6 when the show was cancelled.