Even common names can have non-standard readings. Native Japanese folks mix up readings for names, and need kana sometimes. Personally, I've never yet encountered any Japanese names beyond extremely common ones that I've not at least become suspicious whether I'm reading them correctly.
So I don't think ChatGPT's bad in that regard, if it can at least offer a few possible suggestions. The readings of names can be so damn arbitrary.
I'm sure this problem can be solved. The linked article suggests a promising approach--more and better Japanese data.
It's not only people's name, it's also place names. Example: https://ja.m.wikipedia.org/wiki/%E5%85%AB%E5%B9%A1
Native speakers can do this as well. See "Yagoo" meme; Motoaki Tanigo, CEO of Hololive, is universally known to fans by the wrong name because one of the vtubers read 谷 as in 渋谷 "Shibuya" rather than as "tani". https://en.wiktionary.org/wiki/%E8%B0%B7#Japanese
Japanese is phonetic except when it isn't.