To our 3DS Mighty Gunvolt Burst players in North America, we sincerely apologize for the issue with the update file and DLC not appearing in the eShop when it was supposed to.
We worked with Nintendo of America to fix the problem, and can say with 100% certainly that the patch will be on the eShop when it updates on August 3rd at 9am Pacific Time.
Since the patch will be releasing one week later than anticipated, the free download period for Ekoro on the North American 3DS eShop will start on August 3rd and go for two weeks from that date through August 16th. Please note that this extension of the free download period only applies to the 3DS in North America, and nowhere else.
Thank you for your patience!