Unconfirmed Google Ranking Algorithm Update; Is It Product Reviews Related?

Starting around Friday, April 30th but really spiking a lot on Saturday, May 1st, we are seeing signs of another big Google search ranking algorithm update. There are signs that this update had a big impact on the Product Reviews update as well. It is hard to say if they are separate or maybe Google rolled out something, unconfirmed, that impacted product reviews and other categories of sites?