You can't say like FF games, they all have a specific ending. The acception to this is FFVII, where all the games have either lead to a point we've already seen or leave a definite way for something else to happen. For example, in the original FFVII, it ended with Meteor clashing with Holy leaving everyone wondering "What happened to everyone?" Crisis Core and Before Crisis both lead up to the original game. Advent Children showed Sephiroth reappear with a wing and state that he would not remain only a memory before leaving, making you think he's coming back. The secret ending to Dirge of Cerberus had Genesis show up and fly off with Wiess's body. All the games left their endings open for new games, and the FFVII series is over yet.
Kingdom hearts is like that in how at the end of the first game, Sora, Donald, and Goofy ran after Pluto. Chain of Memories ended with Sora going to sleep and Riku taking off. KHII ends with Sora, Riku, and Kairi recieving a message from the king. And now Birth by Sleep leads into the original game and 385/2 Days leads into KHII. Coded is the only game that doesn't follow this way as it happens after KHII making it the farthest game into the timeline, thought it doesn't appear to be signifigant, yet.
As long as these games keep ending this way, both series show no signs of stoping.