I posted a review about a well know energy supplier, which was based on my actual experience. It made no reference to any individuals, promotion, or exaggerations. It had actually been acknowledged on Trustpilot by the company that they made an error!
Yet, last month Trustpilot suppressed my review claiming it had "been flagged and removed by our automated software for having promotional references or suspicious review patterns." I contacted them to dispute this and they ignored my multiple email.
It very much appears to me that Trustpilot work with businesses (that can afford it) to improve there rating, via various methods, including suppressing negative reviews, all to the detriment of consumers.