Despite headlines like this, prediction markets actually help surface insider activity like this rather than cause it. These ppl could have always profited from insider information about these events more discretely and in larger size by, for example, shorting oil at the right moment. It would be much harder to attribute such profits to insider trading. The narrowness of event contracts, and specifically the public nature of onchain PMs, is a feature that makes identifying and tracing suspicious activity easier in practice.
