Hello Not_a_Lone_wolf,
You can "disable" the account by removing all privileges for the user by changing the "role" to "none" using the command:
::> security login modify -user-or-group-name public -role none -application snmp -authentication-method community
Here is a reference document to change the role:
Security Login Modify
As long as you have an SNMPv3 user-created, which it looks like you have with user "general", deleting the user public won't impact SNMPv3.
Here is also a KB with more details on configuring SNMPv3:
How to enable SNMP v3 in ONTAP 9
Regards,
Team NetApp
Team NetApp