I know people are anti-birdsite, but with Elmo taking down accounts with no activity, it makes me sad for all the people where someone died, and their account is a type of online memorial.
Twitter has no official policy on what happens to someone’s account when they die. There is no legacy transfer to a family member or friend, only the option to delete.
Unless you arranged with someone to access the account post death, it sits there or gets deleted.
P.S. You can transfer your FB, Insta, and Google to a family member in many instances; If you set it up before you pass.