Will Apple reject apps that has Login on the first interface? (Minatory Login/Register )

Old question, but for reference I've not had a problem with an application requiring sign-in and presenting an initial login page.

It does offer a guest mode, and the now mandatory Apple Sign-In, but it has not been rejected because it needs a login.

(The guest mode was added after many users left 1 star reviews because it needed a sign-in :-/ )