Out of curiosity, I checked the most recent AP Stylebook that I could get my hands on and it has this to say about Russian names (emphasis mine):

Russian names

When a first name in Russian has a close phonetic equivalent in English, use the equivalent in translating the name: Alexander Solzhenitsyn rather than Aleksandr, the spelling that would result from a transliteration of the Russian letter into the English alphabet.

When a first name has no close phonetic equivalent in English, express it with an English spelling that approximates the sound in Russian: Dmitry, Nikita, Sergei, for example. If an individual has a preference for an English spelling that is different from the one that would result by applying these guidelines, follow the individual’s preference. Example: Foreign Minister Sergey Lavrov.

For last names, use the English spelling that most closely approximates the pronunciation in Russian. Exception: the “ev” ending of names like Gorbachev may be pronounced “yov.” If an individual has a preference for an English spelling that is different from the one that would result by applying these guidelines, follow the individual’s preference. Women’s last names often have the feminine ending “-a.”

But use this ending only if the woman is not married or if she is known under that name (the tennis player Anna Kournikova). Otherwise, use the masculine form. Russian names never end in off, except for common mistransliterations such as Rachmaninoff. Instead, the transliterations should end in ov: Romanov. Also, Russian names end in “sky,” rather than “ski” typical of Polish surnames.

...so by their own rules (and common sense) they should simply be using his preferred spelling, Zelenskyy. And even if they chose not to for whatever reason, their guidelines also say not to do literally letter-for-letter transliterations! Granted, this is from the 2022-2024 Stylebook, so it could be out-of-date.

Actually, on further research, I realized this is actually a Reuters story! AP News uses Zelenskyy, while Reuters appears to consistently use Zelenskiy. I couldn't find a recent Reuters stylebook, but the one I did find only had specific guidance on Chinese and Israeli names. Very odd choice, regardless.