No, not all poetry is art. It's just a mode of speech.
This poem will not survive its time, as Shakespeare's have. It will not be preserved by those who tread the boards. It may be buried underneath the morning news. It lives in randomly accessed memories. It does not limn. It does not need discussion. It won't be heard in English class. It means no more than what it says.
It's just a message someone leaves behind.
1. Heroic Couplet
2. Heroic Couplet - Part II