Rengars passive should not allow him to jump to targets that have vision of him in a brush

Because c-counterplay?

On release Kha'Zix, his evolved W would proc his passive on monsters and minions as well, and his passive would not recharge if the enemy had vision of you, even from wards. Meaning: fire an evolved W and hit anything and you'll know if there's any wards or not. They didn't fix it for a good while until they reworked his W evolution entirely.

jumps from bushes all the time