TES has more issues with voiced PC than fallout because of all the races and also you can select age and background freely, ESO if fully voiced but not the PC.
In Fallout its much simpler, you are human and say 22-35 years old in FO4.
I have never really noticed that the player don't speak honestly, I think it will work out well enough, one issue is flow, you know that your are about to say as you selected the option, now you have to wait for your character to say it, think the switch viewpoint will be annoying, most of the dialogues are boring like talking to shopkeepers.
Also an major issue then your character says something else than the description, this is mostly caused by the stupid four option only dialogue system arranged in a cross.
4 options only is more of an issue as it will either require deep nesting, cut options or long monologues.
In short voiced PC has good and bad sides, the 4 option dialogues with 10 character texts is another genius decision like Skyrim quest log who we all love, especially the minor quests with their 5 word descriptions.