Cloudflare has said pirate sites as clients - they are not (and cannot) block any pirate sites that are not their clients. The remedy is for those sites to no longer be patrons of Cloudflare.
If an analogy helps anyone understand better - imagine you have a lemonade stand. You use your neighbor's yard to set up the stand for some reason (maybe since its closer to a main road, the why doesn't really matter). The city tells your neighbor that they will be fined if they continue to have a lemonade stand in their yard, so your neighbor parks their truck in front of the stand, hiding it from the street.
In that analogy, cloudflare is the neighbor and your lemonade stand is the pirate site. You aren't prevented from selling your lemonade, but you can no longer freely use your neighbor's yard unless you want to direct people around the truck ahead of time.