I am baffled by this statement as it seems to be straight up nonsense. Yes, in D&D there is an objective answer to what is meant by "Good". But having an objective answer for what is good does not solve many or even any moral dilemmas. So this is fundamentally obvious and I've explained why it doesn't solve any moral dilemmas so much in this thread that I'm at a loss how you can assert your claim axiomatically without any attempt to defend it. I feel like you are fighting over the label and not any normative, ethical or moral claims. Are you just offended that something is called "Good"? Is the label so important to claim?
If it's not important, why does it need to be given to the powers in the game?
So, what's your favorite moral quandary when an oracle of a supreme being can tell you which of two choices is more good/less evil?