I've listened to the voice from the video and although it does sound good as expected, the intonations are wrong in multiple times. Gives wrong impression to me.
Personally when it comes to voice acting, I could care less if it's from real person or AI, I have no favorite voice actor anyways. If the speeches are carried properly with correct intonations and consistency, I'd give them a pass.
Do you believe AI voiceover is preferable to no voiceover (including the option to disable it)?
If the voiceover is as bad as in this example, I rather disable it and use my imagination instead.
Should the game notify the player that an AI voiceover is being used?
There's no need.