When a user account is deleted, their recipes are kept, but the ownership information is removed. This leaves recipes without an owner, but all other access rights for existing users are preserved. This is not a problem per se, but it should still be resolved in some way that grants new ownership to those recipes.
The easiest idea is to transfer ownership to the anonymous user, making the recipes publicly available for everyone.
When a user account is deleted, their recipes are kept, but the ownership information is removed. This leaves recipes without an owner, but all other access rights for existing users are preserved. This is not a problem per se, but it should still be resolved in some way that grants new ownership to those recipes.
The easiest idea is to transfer ownership to the anonymous user, making the recipes publicly available for everyone.