IMO, I think Marriott uses STAY ANYTIME differently than us FT'ers....
When Marriott launched the STAY ANYTIME awards, I thought it would literally be that - you could stay anytime at any property on any date - no blackouts or full properties ever.
But I have since come to think that STAY ANYTIME in the Marriott world means 1) when regular reward room availability is exhausted or 2) when there is a special event or other reason rates/rooms are high/scarce.
IMO, I think that STAY ANYTIME rooms are limited just like regular MR rewards or special rates, and when they are gone, they are gone.
I am basing this on a few times when I wanted to use them, and could not - but what I also noticed was that when I tried to PAY for the room, either my plat privilege invoked (ie, I could only book one room) OR only suites were available.
Perhaps Marriott needs to change the NAME of this award - to something along the lines of "Premium Availability".........