I just invoked my GDPR right to delete/close my account: https://www.linkedin.com/help/linkedin/answer/a1379064/ and got this result:

Your LinkedIn account is now closed. Although you no longer have access to it, it’ll take a few weeks for your public profile to disappear from search engines. Your data will be deleted as described in section 4.3 of our Privacy Policy

So at least this still works.