I might be going a bit off topic here but bear with me...
It's what you mentioned, Krusha, about how this mistreatment has been given. I have been an AKB fan for almost 3 years now, and I still don't know most things about the function of 48Group, but I do realize the favoritism and the mistreatment of other members, and it does get me upset.
I realize, of course, that it's the focus on the center position and the highlight of the senbatsu members who get the best treatment (as well as the fans/wota who go all out to support the ones they love and want to support). But I feel that each member of not just AKB, but each sister group, is equally important for the function of each group.
Each member has their reasons to graduate; some take a short time to graduate, others spread the time longer. Examples are AKB's Tsuchiyasu Mizuki (who graduated 9 days after the initial announcement) and NMB's Takano Yui (graduated just about 3 months after initial announcement). I know that it could possibly be next to impossible to do, and I might as well say that I'm dumb to say it, but it would be nice if each girl got even a small section of a concert (concert, not just a theater graduation) to recognize her graduation. I'm initially thinking of Marinchan, my love; she's graduating 2 days from now, and I'm still in sadness. But it's only a theater graduation. Marinchan has been in senbatsu once, for Ue Kara Mariko, and is close with Mayuyu. But she has never been ranked in the election. I personally say that she should have had at least just one song where she was center.
I'm simply overthinking and wishing this, as it is pretty much impossible to happen - I mean, what would fans think if a member has such a dedicated time in a concert and they barely recognize the member??
As I went off topic and off on a rant, I feel bad that Mocchi was treated like this. She was once leader of Team B, after all. There could have been more. 
But what do I know.
I am happy, though, that it was a little bit dedicated to her. She looked gorgeous in her dress and judging by the picture it looked like a good performance for Team B.
