Besides the visible Twitter username, Twitter also has a unique numerical ID for each account that won't change even if the account changes its handle. The ID can be accessed in the page source or the link when selecting the report account option. For example, the MusicBrainz Twitter account has a numeric ID of 21464213. This can be formatted as either:
https://twitter.com/i/user/21464213
https://twitter.com/intent/user?user_id=21464213
https://mobile.twitter.com/intent/user?user_id=21464213
https://mobile.twitter.com/i/user/21464213
Opening the link will redirect the user to the account of https://twitter.com/MusicBrainz