>will not stop them from from accessing my old offline vault with the old password with the now deleted entries as well?

Correct. They have a backup from months ago. While changing your master pw is a good idea, it doesn't remove what's already been taken.

>Within a password file i would keep important private notes, not a secure note, but the field within a password entry,

Everything I've read says the notes fields were encrypted. The URL field was exposed, as well as your name and email attached to your specific vault file.