Ok get some perspective on this:
1: The changes she was working on were obviously planned up until some point in the last week, even at Lavecon she still had the go-ahead from FDev to talk about it, so there has obviously been some kind of change in the past week as to the direction of what will be included in the next major update. Not a bad thing by any means aside from we will have to wait a little longer for that content.
2: Yes, posting her deleted tweets is going to do absolutely nothing for her aside from potentially cause serious friction between herself and FDev, so please stop with that, in-fact it would be very wise for anybody having done so to remove the image captures of them entirely from this thread. They were deleted for a reason, a knee-jerk reaction to a situation should never be disclosed in public and she has reversed that, so do the same if you posted images, you are hurting nobody but her.
3: She has not been fired, she has simply moved on to work on a different area, something which happens regularly in the development cycle.
4: She has not been "gagged" or "silenced" or anything of that nature although there is a good chance that she may well have overstepped her NDA discussing things with the community, however that is pure speculation and may have only resulted in being requested to hold-back a little on the public forums.
5: Her deleted tweets, while appearing one way (if you care to look at it like that) can also simply been seen as being ticked off by last minute changes, something that, again, quite frequently happens in development, however it is usually unlikely the public will ever hear about it as disclosing information of this nature is usually built into the NDA all devs are under working for a studio.
6: The content has not be scrapped or removed from the code-base as far as we know, it has been set aside. It is quite understandable for her to react badly to being told the content she has been working on for 2 months, no doubt with a deadline looming over her head for it, has suddenly been shelved, but that does not mean it was for nothing. The code remains, it will be implemented. There is no way 2-3 months of programmers wages are going to be thrown into the dustbin by ANY studio on earth unless the resulting code-base was either totally broken or unworkable, neither of which I would guess applied to her work.
So yes, I can understand why everybody is upset, SJA is a favourite around here for many forum users and it is due to this the rumour mill is going into overdrive, however this thread is turning a molehill into a mountain over what is most likely nothing.