Given how well known other unscrupulous review service tactics are (eg, yelp) I doubt this would be the case. It's hard to keep such practices secret when they involve attempting to extract money from a large number of businesses. Plus Google seems to be reasonably honest about labeling (even if very subtly) when things are sponsored ads or not.
I would find it far more likely that this is simply a symptom of something Google is well known for doing: Content moderation through algorithms/ML which mostly works but still messes up a lot. Either the wording of the review hit some metric on its own, or the business already was detected as being review bombed and your review got caught in the cleanup crossfire. Posting it twice probably didn't help, as that would further convince an algorithm it's probably not legitimate.