I have a set of Metzeler Z8 Interacts (mfgd in 2012). When new they had a very noticeable heavy waxy/greasy film on the tread area. I don;t know if it's mold release agent, or what, but it was slippery on the road. I could not cut through it with Simple Green or Fast Orange. It just smeared. This makes me think it was a wax vs a grease. It clogged up sandpaper. The only way I found to remove it was to wear it off on the road, just being very careful as I leaned further over the first few times.
This was not just scuffing of the tire's rubber surface. It was actually removing a heavy wax film that came on the tire from the factory.