According to these tools, around November 13 and 14th, Google started showing fewer video boxes or carousels.
The following chart from RankRanger shows the drop:
Here is a chart from STAT showing the drop:
According to RankRanger, around November 14th as well, Google started to show image carousels or boxes 30% less often for the data set they are tracking.
Here is a chart from RankRanger showing the drop: