I don’t know about how much weight that specific hackathon would carry at a school like MIT.
I do know that they practice holistic reviews and the first things they consider are GPA, rigor, Test scores, and LORs.
They have over 20k applicants, from all over the world, submit yearly applications and admit around 1000 ish. @DadTwoGirls attended MIT and he can try to answer your question.
I know that those elite tech schools tend to like long-term ECs. My kid attended Caltech. His main ECs were sports and Scouts. He had a high GPA and a high SAT and strong character LORs from his classroom teachers and Principal.