Thanks to Padoo from the Taiko no Tatsujin Discord for the heads-up! (embedded tweet also his)the taiko no tatsujin plus music pack store will be closed in a little over 31 hours #taiko_app pic.twitter.com/ZI4hwuM9mI— you deserve shrimp house you want shrimp house (@quimeshine) March 24, 2018
Following that previous announcement that iOS's Taiko no Tatsujin Plus will soon terminate the song pack model (and taking the points system and the Fukubiki feature with it), we now have a definite date and time for it: Those features will be removed as an urgently-called emergency server maintenance ends at March 26 2018 17:00.
Be assured that all the songs already purchased will still be playable after the closure, but these will be the last hours for you to make new pack purchases.