Does ECS is supposed to replace oop in unity?

Does Unity Entity Component System will replace oop in unity in future or will it be just an optional way of programming for intensive gpu game like strategy game or large scale simulation ?

Unity’s ECS system is designed to offer a data oriented programming style towards the traditional Monobehavior structure. Monobehavior will still have a place in the engine’s future. Unity’s ECS will certainly improve the performance of CPU intensive games (if you write it correctly) but it will not become the standard for Unity.