About SM statement. It was months ago, well before launching the brand, that Jessica informed about her future plans (probable marriage or leaving SK, whatever). So since then negotiations went about it, and SM was already expecting her to leave next year.
Then her brand was launched. Probable this was without (any or just very partial) SM consent. It was a new thing on the table for and I'm sure SM wanted her to be exclusive to their activities.
In any case news came out they renewed their contracts. We just don't know the details, probable different for different people, but all signed. We just don't know exactly when was signed, only when the news was out.
At the surface, there was no single indication that she was (maybe) neglecting group activities. After Mr. Mr. and the tour, the group just got together only a bunch of times for performances and a few photo-shoots. Of course we can't tell if there were other invisible problems. But the point is that it wasn't perceptible from outside. It seemed it wasn't really affecting them as a group. Tiffany even said about Jessica's brand on Kcon (I think). If the members were displeased at that point, she wouldn't say it.
The negotiations reached some critical point. She arrived yesterday from NY apparently, to depart today for the fan event. It burst at dawn, she was shaken and emotionally unstable, she put the weibo as it was the only form to announce it. Maybe it was not the best choice nor the best words. She is not accusing directly other members, only that it was informed by SM and them (but here is not clear if they actually had any active role).
EDIT: Actually is good she put out some words before SM statement. I bet she was so angry that she had to put that before anything else. At least we have more than always dubious SM statements.
I don't believe they just ganged up as support partner for SM on this. They are also employees, SM employees, and as much they have probable some more liberty now, SM as the employer has the main power. They probable knew about that same time or just earlier that SM decided this outcome. But what they could really do? Leaving, to where? And by doing it breaching their just extended contracts? They would become outcast in entertainment industry, see JYJ. The other option is to put their heads down and accept it against their will and go on with their business.
Here are people saying "they are rich enough, why not leave SM?" Did you considered they want to do what they are doing? Is what rich people do, they still want to work and want to have goals, even if you earn 1 billion.
I agree that this is surely both parts faults, but again, SM is the strong partner as the employer, it has always the upper hand, specially in this industry in Korea. I believe the brand launch without SM getting some part of it has a big role on that, the part of affecting group activities not so much. Even in the brand information, there is no reference to SNSD or SM.
As for Jessica, I admit she was probably giving too much attention to that (adding the relevant support of her partner) and that fuzzed her focus.
In the end, SM was intransigent and again preferred to break others than bending. They prefer SNSD as 8 but under their total control than the much valuable group as a 9 with some signs of doubtful (on their eyes) obedience.
She is still under SM but the situation may become similar to some employees that get pushed into a corner and doing nothing. Let's see.
EDIT2: Actually, if her was so in fault that she screw up schedules, she would be out of SM, not only from SNSD. They are also punishing her for branching out with the fashion brand.
I sad for the the members, they will never be able to free express what they feel and what really happened. We just have so far a clean SM statement, and we will continue to have only that, aside the whole news and "news" that comes up. And they will have to proceed with the activities as if nothing happened, this is the most cringe worthy situation. Sad also Taetiseo comeback have to proceed with this situation (not to mention today's event!).
My dwindling interest on K-pop is now even lower after this, as I followed mainly SNSD activities, from now on it feels wrong and will be hard to get used to this. Time to give away.