PLEASE DO NOT GO THROUGH WITH DIVINE JUDGEMENT
Divine judgement is such a huge nerf compared to intervention. The cooldown is literally doubled and the invulnerability duration is lowered by 33% at max rank. Aside from the fact that this change will completely devastate kayle's support ability this is a major debuff to carry kayle since it is channeled and prevents her from aa'ing (not to mention using other abilities such as flash).
edit: furthmore divine judgement costs 100 mana vs interventions 0!