The bulk of the ballots to be processed/counted are Vote by Mail ballots that require signature verification, extraction & preparation before tabulation. The update schedule allows for larger volumes & makes each update substantive leading to more definitive results trends. 1/
There was (and typically is) a surge of Vote by Mail ballots returned on Election Day -- through the mail, at drop boxes, and at Vote Centers. Much of the work today is organizing the volumes of ballots received and establishing estimates responsive to queries. 2/
Additional valid Vote by Mail ballots returned through the mail that are post marked on or before Election Day will continue to come in for the next several days. Those too will need to be processed and incorporated into the update schedule. 3/