It is possible that they do something and get away with it though, so it is safe to say that you if you don't want to get into trouble, might as well use a DEX or withdraw asap.
If you want to keep Bitcoin and have doubts about CEX, then the best choice is like that. Choose DEX and withdraw all funds from CEX because nothing is impossible. The vulnerabilities that CEX has are not shared by DEX. The OP should follow this method to clear his doubts. You have higher authority over your own assets, no one can interfere. Not only doubts about cheating, you are able to fully decide what to do with your coins. Even so back to individual tastes, no one can blame your choices and views. Doubts will always arise in people who are careful about their assets.