If anything, insurers will just have to be more careful on what risks they take on. So Travis Scott as an entertainer, and any similar events without proper loss control or safety parameters in place, will just be uninsurable. If they aren’t compliant with insurance, they wouldn’t be able to hold events at most venues (unless they can self-insure or the venue has no standards) so it would (and should) limit their crowd size to zero at most venues. Insurance companies aren’t 100% effective at enforcing eligibility guidelines so some risks will slip through BUT being in the industry, I can promise you that everyone I know is following this incident closely. It’s interesting.