Like most others, I’d agree that the night being comp’d is appropriate and obvious.

I also agree that, due to your Plat100 elite status and 500 nights, the hotel going a little above and beyond isn’t inappropriate, either, but that absolutely depends on the brand. For a midscale or upscale hotel, I would not expect more; for a luxury hotel, I’d expect perhaps points toward (but not necessarily equivalent to) another free night or perhaps a food/beverage credit of some kind as an additional gesture of apology.

That being said, it is fair to get only get a free night credit, either by comp’ing the night in question or awarding points equivalent for another night.