A large company is much less cohesive than you realize. You can't reliably reason about the goals of one part because another part isn't consistent. This particular difference could easily be explained by insufficient funding to moderation, which is endemic in social media.
I've said this twice already, it's not that another part "isn't consistent" (I would agree that this is to be expected), they're CONSISTENTLY acting in the opposite manner than is being speculated here and I subscribe to the "purpose of a system is what it does" world view.
If you really subscribed to POSIWID, you wouldn't be making arguments like "That's probably not the goal", as that's nonsensical from the POSIWID perspective.
The nominal goal of the code could well be bots at the same time the POSIWID purpose is about the exec impressing his superiors and the developers feeling smart and indulging their pet technical interests. Similarly, the nominal goal of the abuse reporting system would include spam, even if the POSIWID analysis would show that the true current purpose is to say they're doing something while keeping costs low.
So again, I don't think you have a lot of understanding of how large companies work. Whereas I, among other things, ran an anti-abuse engineering team at Twitter back in the day, so I'm reasonably familiar with the dynamics.
