9.1 Sejuani change was succesful
Sejuani got a soft gameplay rework on 9.1 to make her less overbearing on pro play any time she was even playable on soloQ.
The result on soloQ are this healthy numbers 49.06% winrate 8.22% pickrate and 4.01% banrate https://lolalytics.com/ranked/worldwide/platinum/plus/champion/Sejuani/
And for pro play she's a good jungle but not even close to be as opressive as she was there before.
Giving more dmg to a tank and nerfing her tankiness and utility sounds odd but it's the way to go to make tanks balanced for both soloQ and pro play at the same time.