The concept seems sound. Wood posts rot out at surface level, where water remains standing. This provides a rubber membrane to keep the post dry. From the website, it looks like they are applying a layer of a tar like material, then wrapping it in rubber, then heating it all up to melt it together. The process and materials seem very similar to how a flat roof is sealed.
Does the rubber wrapped around the post become loose when the post dries out or cracks? Does water get in between the liner, and if so, is it significant to matter?
Do power poles ever rot out? I've seen them replaced because of damage, and because they are in expansive soil that causes them to lean over. But just like treated posts, what percentage of them rot out in less then 50 years?
I've replace more landscape timbers used for fence posts then I can count. In every case, they are the wrong material for a fence, and they always have a low area around the post that holds water. I've also replaced several railroad ties used for fences that rot out right at the surface for the exact same reason. I've never seen an 8 inch round posts or a 6x6 post that was rotted out. I can't think of any 4x4's or 4x6's either, but have replaced them for twisting.
For a pole barn, or any building with a roof over it, this is either a waste of money, or a feel good expense. The slope around the building needs to carry water away from the building. If that is done properly, there will never be a problem with treated posts in the ground.