Season Previews have a huge reveal (possible spoilers)

I haven't really heard anyone talking about this but the trailers for the upcoming season revealed a real change with the walkers.

I thought I heard in one preview the walkers actually talking...some people (Rosita and Eugene maybe) were hiding from a horde of walkers and you could hear one of the walkers whispering "Where are they?"

In another scene Jesus and Aaron were observing a group of walkers and noticed they were acting different..one of them said "Have you ever seen them acting this way before? They're evolving "..

But I'm not sure if the walkers are really evolving or it's just the whisperers that wear the skin of dead people..