Won't surprised if it happens. Most ICO's are suffering from big negative once listed on the market because during their token sale someone will take advantage of the bonus. That's why KYC is a must for participating in ICO.
What you have posted doesn't mean anything. What KYC has to do with bonus and value of tokens, it is usually low trading volume and bounty hunters are dumping tokens and nowadays investor wait ICO to finish to buy tokens from bounty hunters at much lower price. Lots tokens don't have real use, they are used to collect money and after that they are listed on exchange. No buy back, no use for project.