A property x is 'self-promoting' if it is reliably the case that performing an action with a higher x-ness rating increases the expected aggregate x-ness of future actions.

This seems to be entirely your invention? I can't find any google results with a similar match.

Based on the title "Some Thoughts on Virtue Ethics for AIs" I'm assuming this is just a formalization of virtue ethics's idea of moral habituation. For example, from Aristotle's Nicomachean Ethics:

Similarly we become just by doing just acts, temperate by doing temperate acts, brave by doing brave acts...Hence it is incumbent on us to control the character of our activities, since on the quality of these depends the quality of our dispositions. It is therefore not of small moment whether we are trained from childhood in one set of habits or another; on the contrary it is of very great, or rather of supreme, importance