Originally Posted by
Tontoro
I’ve often cancelled seats the day after I booked them at t-355, and every single time they went straight back into award inventory. Also did this several times last year at about t-340 (had to adjust booking for various reasons) and again they all went back into inventory.
Whilst that may have been true for you, it can in no way be garaunteed. Murphy's Law would suggest it will probably be true every time until the one time you really need it.