I can’t comment on this much other than the history and capabilities of the API, which has never offered this functionality. Twitter has always taken a strong approach to user data privacy, which is one reason why up until about 2 years ago the API didn’t offer the option to even get an email address from an OAuth login, and developers were required to gather that information separately (this has now changed).
Incidentally, I’ve never used Clearbit but just checked my details, which were inaccurate! I suppose they are pulling the information from different public profile sources, and in my case that’s outdated, so YMMV.