As part of the latest Campaign Standard Release 21.3 - September 2021, the Quarantine vs Denylist section has been updated with further clarification.
It has been clarified that quarantine and denylist do not apply to the same object and has also been detailed out which ones applies where and when. Check out here for more details: Quarantine vs Denylist
Feel free to reach out through below comment section for your queries and feedback.
Sukrity Wadhwa