Why is this man’s name spelled this way in Roman letters? (I assume the native spelling is in Cyrillic.) Is this based on pronunciation? Is Vododymyr supposed to be pronounced differently than Volodimir would be? How would the pronunciation of Zelenskyy differ from Zelensky?
I think it is just an artefact of the transliteration system one is using. I have seen various spellings of even that one guy’s name.
As for the prononciation, I don’t speak Ukranian but I think there should be a consonant or diphthong at the end of the name, so that you have a “yy” (or however you want to spell it in Roman!) rather than a “y”, cf. the native spelling ий
ISO 9 has И = i and Й = j, for that matter (along with І = ì and Ї = ï)