Katarina instantly ults if at full mana TFT

Katarina with darkin, seraphs, and ludens decides to instantly ult when no one was in range (right at the beginning before she jumps). Given that they just changed how ults work for a bunch of people to ensure that someone was in range of the ult, what I would consider expected behaviour for this would be to ensure someone was in range first, then if not jump to the backline and then instantly ult.