Walensky must have seen that "generally", prior to August 2nd, 2021 when Johns Hopkins Medical Facilities published this article...
https://publichealth.jhu.edu/2021/new-data-on-covid-19-transmission-by-vaccinated-individuals
A pandemic of distrust, and purposeful timing of misinformation and disinformation results in Fear of the Unknown ..."We did not know this fact to be true at the time, therefore it was accurate at the time. Later, we find out that this was true and let everyone know there was more to fear about this cold and flu virus." would have been a more accurate full disclosure answer.