Marriott did this for me a few years ago. (They called it a Reverse Challenge at the time.) My understanding then was that it wasn't their normal mode for a challenge, but if a given situation warranted it, they would.

Over the last few years, they may have moved toward this being more of the norm, or possibly everyone here just happened to meet whatever their "criteria" is for a Reverse Challenge. And I don't know what the criteria really is. I can only say that in my situation, I had been a Plat for many years. Due to a job change at the time, I had a couple of years of less travel. I had actually dropped to Silver, but had a couple of reservations with more than the needed Challenge nights for Gold. So I called MR. They looked at my reservations, and said since I had been a loyal member for quite a while they would provide me with the Reverse Challenge. (With the understanding that if I didn't actually get those nights in with the 90 day period, I would lose Gold again.)