The reason Zhou Tian has so many apprehensions is simply the fear that his actions might affect his plan to develop the Abyss World. Now, given the opportunity to contact those unmodified Angels, once Zhou Tian has successfully achieved his ultimate goal, what consequences his actions might entail afterwards naturally become unimportant to him.
Even if the Light God King notices something is wrong and prepares to enact divine retribution on Zhou Tian, even if the entire Angelic Paradise goes mad – what does any of that have to do with Zhou Tian?
As long as his objective is achieved, Zhou Tian will immediately lead those Angels to flee, so that after Zhou Tian and his group leave, no matter how unhappy those Angels and the Light God King are, they wouldn't be able to find Zhou Tian's people, thus losing any chance to revenge against Zhou Tian.
