Hey Ramit, glad to see your enthusiasm.

For your answer, I don't think all the students pursuing some online course will gonna be eligible for GSoC 2021. As per my understanding coding schools provide a sort of complete structured training of various skills related to computer science in a structured manner and are not limited to a single course on MOOC platforms like EDX or Coursera.

Ofcourse, there is a lot more left to be announced by Google for the program changes. So, just wait and keep an eye.