The New Knowledge whitepaper[0] on the Russian social media interference operation noted several times that Facebook could've provided a lot more data than it chose to release (i.e. relevant FB comments, the number of users who interacted with fake content who also went to the polls, etc.) A lot of important context was intentionally left out of their release that could've helped researchers better understand the tactics and effectiveness of the operation.

We're never going to get a comprehensive answer to the questions underlying these operations as long as companies like Facebook get to pick and choose what data gets released to research these issues.

[0]: https://www.newknowledge.com/articles/the-disinformation-rep...