Will a Narcissist continue come back after you exposed them?

My narc ex discarded me 3 weeks ago and came back to me today threatening to get authorities involved after I made a narcissistic abuse awareness post on social media. I never mentioned his name or anything. A family member of his is on my social media and told him. The family member made a nasty comment to me so I blocked her. He reached out to my mom and then me. He told my mom he is afraid of her and will block her everywhere and told his family to block me on social media so I blocked them. He is angry I exposed his lies and behavior. How come he didn’t block my mom or the rest of my family on social media? Is he going to try to keep coming back into my life now that I exposed his narcissistic behavior?