Yup, Zexal is apparently getting a final adieu with a fifth soundtrack CD.
Amazon.co.jp is listing a 5th Zexal Sound Duel on sale for November 19th, 2014. Presumably this should be legal through websites like CDJapan.
And it’s a 2 Disk deal.
And it’s currently on Preorder on Amazon for 3888 Yen.