Why can Yasuo ult be cancelled by GP Orange and QSS

Because 'suspend' is not the same as a 'knockup'?

As far as I know the only CC they can't remove is knock-ups. Yasuo's ult is not a knock-up, it's a suspend. Honestly didn't know they worked on it, but it doesn't surprise me either.

Honestly think they should work on knock-ups too anyways.

Because you know, that's their intention.