Reina put up a brief announcement on her blog:
I'm quitting ＬｏＶｅｎｄｏЯ。
With that mere sentence, she brings us this weighty news.
Very much like Reina - no frills, no explanations, no room for misunderstanding - just a single sentence.
Also of note: A blog post by Takagi Sayuki, posted earlier on the same day
Today I、 Takagi Sayuki have something important to say。
I love Tanaka Reina-san、 and I thought I'd work hard in order to become a person like Tanaka-san。
However、as of today, I will be graduating from being a Tanaka-san oshi。
And Tanaka-san、 thank you very much for everything up to now。
There were a lot of times、 when I was able to do my best thanks to Tanaka-san。
From now on、 as I'm a senpai, I'll work hard in order to become a presence that will be admired。
Could this be related to Reina's cryptic announcement? Only time will tell.
EDIT: Also, see this post from Sato Masaki
Translation of relevant bits:
And please listen
I despiーーーse her
（please read the portion which follows after once it's past midnight）