Is Walmart Subsidizing Coffin Shelf Reviews?

A lot of people were messaging me about a review change on amazon. People are saying, hay, i've noticed that now only the latest reviews are our showing up on the top reviews. One thing i'm interested to see is is walmart subsidizing any of this for third party sellers? Like, can i get walmart rewards on a coffin shelf on amazon, or is it only for walmart products? That's something that is worth keeping an eye on.