At the risk of sounding like a hater (and I assure I am not, just check out my Koharu GOTW post), this graduation concert has tohe potential to be crying-free. Tears, maybe, but I really don't see real emotion blubbering going on at all.
Think about it. The most emotional grads were always ones for the elders, with at least 2-3 younger generations (and in Iida's case, 5 o_0) to have history with. Even Maki's had a fresh-faced 5th gen to work with.
5 and 6 gen have waaay too much history with each other pre-7th gen, and we've already gone over the general lack of chemistry with Koharu anyway. But more importantly, check out 8th gen, who have the burden of throwing out the "Oh senpai you taught me many things I'll never forget baaww" messages this time around. You have Mitsui, who has a more mature image already, and...yeah I don't see breakdown happening. Jun might cry because that's her thing, but on the other hand her thing with Koharu was arguing.
Not to mention she's older, so she'll probably have a nice message but be kind of embarrassed about it at the same time. And I've never seen Lin cry. I can't even imagine it o_0.
So yeah, I think this graduation concert is going to be kind of weird.