Sharing Advanced Data Protection iCloud Drive Files

What are the implications of enabling ADP on shared notes and iCloud Drive folders/files when the other person(s) involved do NOT have ADP enabled? Will sharing continue unencrypted, or will the other person lose access? I'm not referring to the "anyone with a link" option, just individual users.

I can't find this info in the Apple documentation on Advanced Data Protection (ADP):

In most cases, when users share content to collaborate with each other—for example, with shared Notes, shared Reminders, shared folders in iCloud Drive, or iCloud Shared Photo Library—and all the users have Advanced Data Protection turned on, Apple servers are used only to establish sharing but don’t have access to the encryption keys for the shared data. The content remains end-to-end encrypted and accessible only on participants’ trusted devices. For each sharing operation, a title and representative thumbnail may be stored by Apple with standard data protection to show a preview to the receiving users.

Selecting the “anyone with a link” option when enabling collaboration will make the content available to Apple servers under standard data protection, as the servers need to be able to provide access to anyone who opens the URL.