Apparently, another surprise Persona 4 Arena: The Ultimax Ultra Suplex Hold location test is currently underway, said to last from November 14 to 20, 2013.
Details from the location test can be found in this constantly updated Google document that compiles all of the information people come across.
Persona 4 Arena: The Ultimax Ultra Suplex Hold is set to be released before 2014 in Japanese arcades.