Isn't the "Do I live in a simulation?" question practically indistinguishable from the question "does God exist?", for a sufficiently flexible definition for "God"?
For the latter, there are plenty of ethical frameworks, as well as incentives for altruism, developed during the history of mankind.
On the grounds that those ethical frameworks rested on highly in-flexible definitions for God, I am skeptical of their applicability. Moreover, why would we look at a different question where we redefine it to be the first question all over again?
Very comprehensive analysis by Brian Tomasik on whether (and to what extent) the simulation argument should change our altruistic priorities. He concludes that the possibility of ancestor simulations somewhat increases the comparative importance of short-term helping relative to focusing on shaping the "far future".
Another important takeaway: