What else? I remember reading something this past year about Olivia Wilde having a Beyonce-themed birthday party for their toddler son & that she almost gave birth to her daughter at a Beyonce concert a few months. But all that tells me is Olivia Wilde is into Black music. Jason Sudeikis is too high profile an actor for me to believe that he's Olivia Wilde's beard especially since their married with 2 kids together.
Also the OP has yet to explain why he thinks all the people he listed have Beards. I'm thinking he has confused having a beard with having sidechicks and/or having an open marriage.
I think mainly for her near obsession with black music/culture. From Kendrick Lamar, Drake and Chance 'the motherfucking' Rapper to Lebron James and the 13th documentary (mass incarceration of black and brown men). It's rear that you see white Hollywood movie starlets like her acknowledging their love for black culture. I don't know, maybe I'm looking too much into it.
I don't think you are grasping the meaning of the term "beard". Please explain how she is a *cover* for anyone?
Scarlet Johansson is married to and has a child with a guy who is not in the business. She had said in an interview that she likes geeks and nerds because she is one herself. She likes guys who are themselves and are into what they do. Her husband is what she likes in a guy(however not like her marriage to actor Ryan Reynolds).