It's strange that Quad9 openly does malicious domain filtering [1] using what it terms "threat intelligence feeds", but apparently filtering piracy domains is technically impossible and not the right place for this to happen. I think courts rightly are suspicious of this kind of doublespeak from DNS companies. If DNS filtering is effective for protection against malware and ransomware, it will be at least somewhat effective for piracy filtering too.
[1] https://quad9.net/service/threat-blocking/