Wow, this is quite some news. No one was suspecting this, but I guess it somehow makes sense.
Konkon is so intelligent, it was clear that she would be studying one day, and personally, no matter how much I love her, it's better for her. Even though she has learned to sing (yes, she can hold a note!), what would she do in H!P after just graduating MM? She's not the typical idol and this decision just makes sense.
Makoto was never one of my favorites, but still. I could see her continueing her idol career as an actress, but considering her studies abroad she doesn't seem to want that path.
I hope both will be happy, because they are amazing girls and deserve it.
On another note ...
Two different graduation dates??? Konkon 27th of July, Mako on the end of August. So I guess that means that Konkon will graduate during one of the first concerts and Mako's grad is the last concert of the tour?