I don't usually go ham on rrats and all of that, and this is basically a shower thought:
Isn't it kind of interesting that Pekora and Marine are the emotional ones, while Noel and Flare aren't? A lot of speculation about what the leak could be, but it just struck me that the two in the supposed lesbian couple are the coldest. Maybe she leaked something regarding the reality or lack-there-of of their relationship. A scenario like, 'other members play up characters all of the time. Noel and Flare aren't real thing. . .' You get my drift. That would be something that could piss off a decent amount of people, and it would explain Fubuki being withheld given her closer friendship with Flare.
Again, just a thought.