I'm not really seeing it.
That's kind the same as old Mao ult + old Galio W but only single target, with some additional AS % tacked on for the appeal. And the durations are so short that this would literally become a worse anti-burst tool instead of how it's being used today. I'm not really seeing Kayle just forgoing her Invulnerability since to me, this ability is what makes her her.
And i understand she's going to be GA'd and she would change but in that regard, i think that her Q, W and passive are lackluster abilities in her kit but also that her E and R (with Guinso and Q's slow) create some low points in gameplay, not leaving her targets much of a choice between hard CCing her until her ult expires and then attacking or running away under the same conditions.
I also believe that she should be supported in her support role because the way she is now, she's only viable if her team is facing a lot of burst threats. Her W and R are her only supporting spells in the bot lane.