If the deceased did not leave instructions regarding their accounts, there are a few factors for executors to consider.
A memorialized social media account could be visited by grieving loved ones, and any photos or information posted publicly could still be seen by visitors hoping to retrieve some memories.
However, any public presence could still pose some privacy concerns. Scammers might try to impersonate the deceased, for instance, if they learn about the death through a memorialized page.
With these factors in mind, it might be worth keeping public accounts for a certain time period before taking them down entirely.