Nowadays LinkedIn became an open network, with 645+M members there´s all kind of minds and good people, if you see a poem or boetry in the feed and does not match with your purpose, stop follow, disconnect or block this member. Cheers...
It definitely isn't a disruptive thought, there are many users doing it. It also depends on various factors like if the user who posted is is an author, poet or a copywriter? Right? As far as it is something that engages their audience, it is okay in my opinion.