Even Paul Sherwen said something about him having something to learn, hinting that his Team's PR department might like to teach it to him. I'm sure he will mature, but FFS, he's in the TdF NOW! He should already be au fait with interview and post-ride etiquet, he didn't just start racing last week!
It's face-time that the team sponsors are looking for, it gets exposure for their products and services, if interviewers develop a dislike for him (particularly if he isn't actually either winning stages or a contendor for GC) then the sponsors will worry, and so I imagine will the team manager.
Dave.