After the early tastes of the collaboration event on Taiko Plus' website and Sega's Youtube channel, we finally have a proper Internet corner for the event, fully spilling the beans about its content.
For starters, the campaign will also affect the Android-friendly Taiko game Shinkyoku Tori Houdai, bringing both the short and regular versions of the Chain Chronicle Medley on other not-console portable devices. We also come to know that the collaboration content on Murasaki Version arcades will be available only from August 18th to October 13th.
For more details about the event, check out the collaboration's website here!
Addendum: Normal Battle Medley is only the first part. Expect the new song Chain Chronicle Final Showdown Medley (チェインクロニクル 最終決戦メドレー) in one of the new Vita1 DLC packs on August 6, and later on Murasaki with its exclusive Full Combo title. (source)