Wondering if moles hurt iris plants. And if so, what can be done to keep them out of the iris beds.

Sadly, I am suspicious that they do.

Moles eat worms and grubs, not roots and plants. The only damages they do to plants is pushing them up and out of their way. Or by diverting the water away from the roots with their tunnels. Their tunnels will also be reused by other rodents, such as voles. It's the voles and gophers that will destroy your garden, not the moles.