No glass. The lion and cheetah exhibits in this new area have multiple viewing platforms with black mesh, which I find far preferable to glass. It is very easy to shoot through with a telephoto lens and there is no glare in the bright Arizona sun.
I like that they're using the black mesh. As you've said, it's easier to take pictures through when using a zoom lens. The only thing they need to add is some kind of shade structure, although that one tree seems to provide some. Hopefully there'll be more...