Hmm - I know you can certainly enable/disable avatars from being uploaded, or send new avatar uploads through moderation... but I'm not sure you can "lock" them like how you can with other profile fields.
Is it more of a user experience thing (like users accidentally delete), or they go out of their way to delete?
Thank you for your reply!
I'm not entirely sure if it's accidental or not. I think it may be a user preference- that they go out of their way to delete.