You are correct that his edit is fair enough, but the basis of his what the argument reads to be is worthless, at least in how he approached it. 'Gravity is just a theory' is a classic r/iamverysmart - it's just an attempt at a flex of understanding of what hypotheses are, and this is what the comment seems to boil down to, to the average eye.

Just as with any academic field, it is important to phrase your argument correctly - and he presented his point as what comes off as just "ohoho look how silly these publications are for stating how drastic a breakthrough this is when hypotheses are not fact, ohoho I am smart, they are not!" when his actual core point was "I don't understand why these publications are stating that this is now fact when it remains unproven by the breakthrough in question."

Unfortunately for him, non-scientific-minded users aren't going to give his argument the benefit of the doubt, since he decided to raise and discuss the 'gravity is just a theory'-esque aspect of it in what appears to be a scoffing way. While fair, the edit did his comment no favours to anyone reading it thereafter, only serving to reinforce what his argument seems to be rather than the crux of it.

And at the end of the day, he did choose to make the 'gravity is just a theory'-esque point, which I would argue does (unfortunately for the rest of the comment) mark it as an iamverysmart regardless of his core point. The scoff exists within his argument, and therefore condemns him.