As long as you're not representing yourself as actually being the person, I'm pretty sure it's fairly unregulated. There's all kinds of people who make their living doing impressions of other people, and while it's not strictly a deepfake, it's similarly making an imperfect copy of someone else's voice. It might be different if you're directly using recordings, but that's another underregulated aspect of AI -- they soaked up all kinds of stuff without any repercussions.