Minix0
They upped the tick rate from 30 to 60 in 1v1 matches with no spectators. This means the game will check inputs every frame instead of every other frame, leading to less dropped inputs overall. This benefits stable connections by quite a bit, leading to 1 frame of less input lag minimum, and making the game more responsive, but for choppy connections, the game will be a bit worse because due to more packets being sent, the game will freeze more.
TL;DR Ultimate is a 60fps game, so increasing the tick rate to 60hz makes it better for the online as now the game will check for inputs every frame instead of every other frame.
TL;DRTTL;DR: Online went from trash to borderline playable.