You won't get a reply from the editors identifying specifically which parts are hate-speech. You won't get a notice of what policy you violated other than a general referral to a policy provision. Corporations just don't operate that way. They won't publish the poem to allow comments from Medium's readers about whether and what is hate-speech.
The only way you will get an airing of the poem is to sue Medium. You would lose, but the poem would be published in your complaint. Note, I am not advising that you sue. You might get the issue aired on Facebook or Twitter if they felt like taking on and embarrassing a competitor.
What I advise is to adopt "lawyer tactics." You make numerous statements of fact but you provide no proof, no specific, objective, proof on record. You state that these facts are well known. I have highlighted some of the alleged facts you need to prove.
Prove it.
Write another article proving each factual allegation you make.
After you have a proven statement of facts, write a "statement of law." Find and layout in objective, logical format the correct definition of "hate speech". Use accepted guidelines like any Associated Press guidelines. Search the Net for authoritative definitions. Lay out the "law" in objective neutral language.
Then, make an argument that the poem, though perhaps controversial, is not hate speech but simply a recitation of facts, however uncomfortable it may make a certain group feel.
Send that article to Dr. Yildiz. I think that if you prove that all you do is reference proven facts and make an appeal for a boycott, and if you lay out a correct "standard of law," he will be fair in his determination.