The more I think about it, the less should it be surprising that WSG put Kizaru down.
1) Gear 5 is a physical powerhouse, stronger than any character we've seen
2) Conqueror coating that can compete with Kaido
3) Internal destruction
Borsalino's fighting style was clearly shown to be focused on maintaing the distance and using his superior speed and range to prolong and win the fight, he just got caught in the end, partially due to not being truly focused on achieving the goal.
So I think his "redemption" will be moreso his full commitment to either World Government or (more likely) saving his old friend Vegapunk.
I really love kizaru I don’t care if he’s weak or strong I just want him to be happy