Earlier quoted context omitted.
"We have no evidence that this was exploited" is a standard psychological trick they pull in vulnerability announcements to give an unfounded impression that it hasn't been exploited.
It doesn't have to be a psychological trick. Sometimes you don't actually have evidence it was exploited - at which point what are you meant to say?
This is a relatively benign case but the same language is used in other breaches when people should be taking measures like freezing their credit or reviewing financial transactions.