In songwriting it’s not unusual for lyrics to be coauthored, and it’s easy to come up with many famous examples. (Lennon and McCartney, for example: though some material credited to both was actually written only by one or the other, many other lyrics were written jointly, or with significant input or revisions from the other.)
However, I can’t recall any famous poems which are credited to multiple authors. Are there any? To be clear, I’m talking about actual collaboration at the writing stage, not one poet’s independent translation or adaptation of another’s work, nor one poet’s completion of a deceased poet’s incomplete poem.
A poem that someone who doesn’t have a particular interest in poetry is likely to have heard about, or maybe recognize a few lines from. I don’t think anything in the article you linked to qualifies, but then again, maybe I’m even more ignorant of poetry than your average person.
William Wordsworth and Samuel Taylor Coleridge collaborated on Lyrical Ballands, a famous and influential volume of poetry; but I don’t know whether there were any individual poems that involved contributions from both poets.
There are some translations of poems that could in a way be considered collaborations between the original author and the translator.
According to Wordsworth’s notes on “We Are Seven,” there does seem to have been a bit of back-and-forth collaboration on both “We Are Seven” and “The Rime of the Ancient Mariner,” although in both cases one poet was clearly the primary author.
The poetry of Katherine Bradley and Edith Cooper, published under the pseudonym Michael Field, certainly qualifies as a full-on collaboration, although none of the poems is especially famous. Still, they’re at least well-known enough to make the Norton Anthology of English Literature.
The Iliad and The Odyssey perhaps, which are thought to have emerged and evolved out of an oral, bardic tradition of recitation. Whether or not there was really a “Homer” who gave them their more-or-less final, written form, you can legitimately see the poems as being collaborative works produced by multiple bards over multiple generations. The same presumably applies to other poems that come out of oral traditions.
Some of the plays of Beaumont and Fletcher are quite well known, and presumably, like the plays of Shakespeare and other dramatists of the period, are mostly in blank verse.