I don’t think metal subscription and car insurance are comparable products really.
I guess people could downgrade at anytime… for those who got it for free as an investment perk might be at a slight disadvantage.
Car insurance is slightly different. Because most individuals pay per year. And those who don’t will still have to pay (unless they get SARN). It is illegal to drive car without valid insurance so it is more of necessity. The car insurance market has been kind I agree (mainly because of lack of cars on the road and reduction in number of claims/accidents).
Metal subscription is more like amazon prime/netflix subscription. If one doesn’t get free deliveries in January Amazon wouldn’t refund the cost of membership for a month. It is up to an individual to review benefits of their subscription periodically and ensure they are fit for purpose 
So if one is not planning to get benefit from metal subscription they should review the requirement and cancel next month.