I am curious have any Mac users gone through the process and gotten a refund for their copy of this game that is no longer functional?
Seeing as they've been able to play the base game for at least 3 years, I'm not sure what the basis for the refund would be? And they'd still be able to play the game on their Mac through the use of BootCamp.
You could make a case for a refund of the Horizons or Life Time Expansion pass, but for the base game, no chance.