I can't watch the video, but from what I can gather they seem to have recorded alternative voiceovers with celebrity involvement and are selling them as optional DLC. If so, then--
--I think that's awesome. There are some "geek-beloved" VO celebrities I'd pay extra to NOT have voiced my copy of the game. There are games I'm boycotting (as in "might accidentally buy in a bundle, and even then push the slider all the way to the left") because of who voiced them.
For me, there are two types of VO work: (1) normal human speech and (2) "talking to a developmentally challenged baby" speech. Anyone without a speech impediment can manage #1, and #2 shouldn't exist outside of talking to actual developmentally challenged babies. Overpaying for either because the sound was farted out by a famous facehole is not something I want to do, ever.