From their "community guidelines" page:
Not allowedMessages that are disrespectful to your neighbors or otherwise violate Nextdoors Be helpful, not hurtful, Ranting, or Over-posting Guidelines.
Read into this what is obviously intended. Only a single BLM sycophant needs to complain to have such discussions censored. Furthermore, the BLM complainer can be as hurtful as he/she/it wants to be, and he/she/it will not be held to account for objectively DISRESPECTFUL attacks (I speak from experience, I was openly threated with impunity.)
This has not been my experience. I had a run in with a jerk and a neighborhood moderator. I stood my ground and Nextdoor didn't butt in at all. Of course I remained respectul at all times. That being said, my knife is very sharp and I managed some deep cuts.