They weren't storing your name in the first place; they've acquired a new service 'blowfish' for which an account is automatically created for you if you currently or in the past have used glassdoor. Blowfish demands a real name to be used at all. (including to delete your account)

Ontop of this, after linking the two services on your behalf; glassdoor will now automatically populate your real name and any other information they can gleam from blowfish, your resumes, and any other sources they can find, regardless of whether the information is correct (users have reported lots of incorrect changes). This is new.