An author can have books in multiple languages, so the only constant available to Manage authors is the interface language.
Edit metadata, bulk and single, operate on books so the book's language is available. However, if the author has books in multiple languages then the answers might be different depending on the book.
If using manage authors then you should enter the author sort value you want for *all* the author's books irrespective of language. The value may or may not be what the compute function produces. This process also allows you to fix problems such as the one you mentioned, Cervantes, others where the de/la/etc
are not "particles" but are instead part of the surname, and east Asian names where the surname comes first without a comma.