Here's my response from the Git, since Necaladun has asked we not discuss anything but code there:
"Boy oh boy, I do not understand the reactions here. It baffles me how admins can say things like "If this is merged, I'll just make all my notes private!". You've just made the case for transparency on your own; if you're intending to hide your notes, I dread to think what they might contain.
I say this as someone who has administrated for a variety of games at a variety of levels for years. I know everyone says "I was a headmin on this one server so I know my stuff" but I do system administration for a living and have done for some time; hiding responses from your clients is unprofessional and breeds an atmosphere of doubt ("If you've nothing to hide, you've nothing to fear" - I hate that particular concept, but some people tend to think that way). That said, private notes would exist purely to ensure admins have a way of communicating concerns about behaviour of a player privately (metagaming/comming, toxicity etc) and the player shouldn't even know they exist. They can ask if there's a secret note and the admin response will always be "I cannot tell you." This is literally how regular notes work now, so people would be no more likely to ask about private notes than they would about current notes.
In the event of admins abusing the private notes system, headmins intervene and slap the admin on the wrist. If an admin is incapable/uninterested in writing notes that are appropriate for public viewing, they should not be an admin, period.
Other servers work like this, so it's not like there isn't already precedent for using a public notes system and they seem to do just fine (except for Oracle - F). Irrespective of the decision made on this matter, admins shouldn't be showing their asses by announcing they'd flout the system; that makes you all look bad by association."
To admins saying things like "Player gets warning, wants to know the contents of the note", you tell them no, like you do right now for all notes. Although they shouldn't even know you've left a hidden message, so that point ought to be moot.