Have you considered it takes a while for cases to filter up or down? Incompetence is usually a better candidate than malice. It could be they'll report it a few days from now, or that these cases were found and reported a few days prior to the 20th and were folded into earlier reportings. For instance, if the cases were identified and reported on the 18th, and the notice was posted on the 20th, that would remain consistent.

Stop with the unfounded speculation and fearmongering.