I believe Williams dropped their requirement for SAT IIs in the fall of 2016, which was probably partially responsible for the 23% jump in applications seen in the CDS for 2017-2018. I remember this because that’s the year my daughter applied and she had already signed up to take the SAT II before she found out that Williams had dropped the requirement.
They both are. The CDS info is published the following fall. So the admissions information for freshman entering fall 2017 is published in the fall of 2017 and is called the 2017-2018 CDS. They haven’t yet published the 2018-2019 CDS, which will include the numbers seen in the press release for the class of 2022.