See OP's confusion in https://stackoverflow.com/q/77031819/5740428.

I believe that the current wording implies the following (I've elaborated on this in my answer https://stackoverflow.com/a/77032028/5740428):

int x = 0; // global variable

void concurrently() {
    x = 0; // may be a data race, even if the value of x prior to this assignment is zero
}

I think there should be a note or example somewhere (possibly [defns.access], [intro.races], [intro.multithread]) which explains that even if the value is unchanged (based on equality comparison), changing the value (in the abstract machine sense) still counts as modification.