Was he a poet? Well, inasmuch as he published in quatrain, I suppose so.
Geoffrey Chaucer, who died over 100 years before Nostradamus was born, also wrote in structured verse form, usually iambic pentameter. However, Chaucer is readily readable by modern English speakers, albeit with a little instruction on Middle English, whereas Nostradamus' quatrains are little more than strings of Middle French words which are essentially impenetrable to modern French speakers and rely on "interpretation". Of course, each Nostradamus scholar has his own interpretation!
Can you interpret this one?
At the time of the preparation of the evening feat
Four intrepid chancers take their stand against the Beast
Untold riches come from interrogation
Or catching leads to damnation