Actually, I think Hyao can. But it will cause a very huge update since most of dialogue and events would be changed. You may think Hyao just need to add options for players to select a pronounce for MC, but it mean Hyao need to redo every single dialogue from the beginning to match with a pronounce you have chosen. Just like a novel with a lot of alter version just because pronounce, body, and gender be changed.
And it will be hard since not only Hyao who writes story scripts but also another guest authors who write it.