I dont think you will get nights for the no show, you also wont get credit for 2 rooms for tonight.

I had a similar issue with a double nights promo a few years ago, and Marriott told me I was SOL, they cannot manipulate nights but offered 2,000 points instead. Took it because the nights werent worth the effort at that point.

If they will cancel the no show and book you tonight and tomorrow instead, that should work