I think it really depends on the context. What are you leaving out about this? Surely the post(s) go into the reasons why.

Possible reasons? The person has too many friends and is having a hard time keeping track of them. Perhaps the person is having issues with harassment, spamming, or other negative attacks. Perhaps the person is taking a stance against things like politics and differences of opinion. Perhaps something has changed in their life (employment?) necessitating taking more control of their social media. Perhaps the person has made a decision to take more personal accountability and responsibility for their social media presence..... I could continue.