If you try reading poetry and get something out of so reading, does it matter whether they "have meaning"? It's the practice, and its effect on you, that matters. Like Zen. You've missed the point if you think there's anything valuable to be found, something concrete you can dig up and take hold of, that when you find it you have it and someone gave it to you.

"Meaning" may be present but is irrelevant if the experience is the same—what evidence do you want? Getting something out of poetry? Many people clearly do, if that's the test.