At this point, I'm not even surprised at this reveal. In fact, I would be more surprised if she had been killed.
There's no indication about the time that has passed by since Neneko's supposed death, and T.O. Neneko fan club meeting.
For all we know, there could be days, or even weeks, in between those parts. And then there's the question of how much time "A few days later" between T.O.'s Neneko fan club meeting and when the Minano AI fan club members surrounded Shinobu.
In other words, it could make zero sense that Neneko's swollen cheeks and bruises would have healed that much, or it could make perfect sense.