Tsunku's comments on the name change:
"2014 will mark the 17th year since the name Morning Musume was given to the group, but in order for this group to continue for another 10, 20 or 30 more years, we've decided to add the year next to the name so that everyone will immediately know the answer to simple questions such as "When did they release the song ______ again?" or "When was ____-san a member of Morning Musume?"
This also means that they will be changing to "Morning Musume '15" on January 1, 2015.
Tsunku though said that: "Once we try this out and if things actually become more confusing, then I'll probably take this decision back. But whatever the case, they will be known as 'Morning Musume '14' come the new year, so please root for us!"
Source:
http://contents.oricon.co.jp/upimg/news/20131206/2031706_201312060671726001386299662c.jpg
