Bad environment, as in SKE48 for years now has been pointed out by fans to have a huge number of episodes alluding to it not having the best work place so to speak. Basically cliques, seniors not being too good towards juniors, girls frozen out from the "good company", and more like this. Of course there's no official confirmation or such, so they can only go by fan observations, social media, comments from the girls themselves, and so on.
Hence why the fans thought she should audition for NMB48 instead - since she's from Osaka, and NMB48 is from Osaka.
At any rate, the announcement she made in today's show was really awkward. She interrupts the bow the girls do at the end of the performance like the girls always do if they announce their graduation. Then teary eyed and while being nervous/emotional, she announces her graduation in a very straight forward manner (and it sounds like she has memorized all the lines she had to say as if someone gave her a paper beforehand). And when she's finished speaking, there's just this long awkward silence with fans going "eeeeh?" and the girls not saying a single thing. Just standing there, and looking at her. Makiko attempts to break the silence, but she doesn't really say anything, and nobody else comments, and it just goes silent again...
Anyways, this to me is a very disappointing graduation. She's relatively new in the group, and she has an interesting personality, but she has not been popular at all.