Apps built to closely mimic another app's UI, icon, or name — or that impersonate a company/individual without authorization — get rejected regardless of whether the underlying code is original.
Template marketplaces are the most common cause: a generic template with a swapped icon and color scheme reads as a copy even when no code was literally copied.
"Your app appears to duplicate the content and layout of another app currently on the App Store. Apps should offer unique content or services..."