I think Kuzan can still have FS. Post ice block he just wasn't into the fight yet, because of his emotional struggle, and looking at it from a meta perspective, blue hole somewhat had to happen, so Garp gets some time dealing with the other BBPs I'd say.
And now it could just be that Garp's all out speedblitz, similar to TB is just so fast, that even FS users have trouble keeping up with it.
I wouldn't jump the gun at hand of two feats, when one is even very, very circumstancial.