The outcome of Thursday’s Phoenix Mercury regular-season finale against the Seattle Storm at Footprint Center didn’t matter. The playoff-bound Mercury lost 89-70, but scenes from the stands suggested otherwise. Handmade signs in the crowd reading, “DT, we’re NOT ready” and “If this is it, I might cry” perfectly evoked the collective feeling of fans attending what could have been Mercury guard Diana Taurasi’s last home game. As the Mercury’s ‘If this is it’ campaign implied,…