They could police their content. Or if they don’t want to, they could meaningfully partner with the security industry - create a “security bots” program, respond to takedown requests in days not months, etc.
I suppose that Cloudflare scanning payloads for known malware could potentially be effective if they could make the performance work.
Closed partnerships programs are a bit concerning though. Once they’re up and running there’s an enormous economic incentive for CF to squeeze members with fees that capture the economic upside.