Reasons
Absolutely none of these reasons explain why we eat cheesecake.
1. Moshe (the one who received and gave us the TORAH) wouldnt nurse from non jewish woman. Therefore to recall his zechus on this day.
That might explain why we drink milk and/or eat dairy. Nothing to do with cheesecake.
2. As mentioned previously now the jews had halachos of Treif animals and shechita their kaylim were treif it was shabbos and they could not do Hagolas Kaylim until after shabbos.
Same as above.
3. Before Matan Torah they were choshed that milk was ayver min hachai and so asur. From the pasuk Eretz zovas cholov oodvash they learnt milk was ok.
Same as above.
4. Chalav is Gematria 40. kineged the 40 days Moshe went up
Same as above
5.The Midrash states that Har Sinai has 8 names, 1 is Gavnunim because it was white like Gevina. So we eat Gevina as a Zecher.
This might explain why we eat cheese, but says nothing about cheesecake.
The Wolf