I left a review on the BBB, when I was a student, after being promised a gift card for a video interview of a product for one of the large tech companie's PMs.
I refused a free trial or some other token offer by a call center employee that the company sent as part of the BBB resolution process.
Not long after,the BBB removed my review even though I offered email evidence between the PM and I. I emailed one of their managers asking for an explanation for why they removed it. They gave me some vague boilerplate that didn't address the issue.
Because they weren't clear in their communication with me on the reasons why, I couldn't help but wonder whether they had some similar incentive in their relationships with certain companies to remove problematic reviews.