That is easy: subscribe to newFontDidOpen and do something with the new font.

from mojo.events import addObserver

class SetInfo(object):
    
    def __init__(self):
        addObserver(self, "myCallback", "newFontDidOpen")
    
    def myCallback(self, info):
        font = info["font"]
        print font
        font.info.copyright = "This is my font"
    
    
SetInfo()

and maybe set this script as start up script in the preferences so each time you open RoboFont the observer will be installed.

good luck