In an official statement Twitter had announced it intended to remove inactive accounts and start to free up usernames before the end of 2019. Initially it was intending to contact everyone who had not logged in to their account for at least six months to encourage them to do so if they wanted to hang on to their accounts.
However, the latest announcement has acknowledged feedback from users about the accounts of deceased friends and family.
“We will not be removing any inactive accounts until we create a new way for people to memorialize accounts.”
Sources: Mashable; Verge; Twitter.